Too many redirection with force https (no replies)

Hi,

Today I try to force piwik to use https, so after buy and install certificat, I try this :

[General]
force_ssl=1

But after that, i am unable to connect on piwik cause of too many redirections.
Piwik works on http and https, this only appear when force_ssl=1 is set.
What's going on ?

Here is my nginx config file :

server {
        listen 80;
        listen 443 ssl;
        server_name sub.domain.fr;
        root  /var/www;
        index  index.php;
        ssl_certificate /etc/ssl/ssl/monssl.crt;
        ssl_certificate_key /etc/ssl/makey.key;
        ## Block common exploits
        set $block_common_exploits 0;
        if ($query_string ~ "(<|%3C).*script.*(>|%3E)") {
                set $block_common_exploits 1;
        }
        if ($query_string ~ "GLOBALS(=|[|\%[0-9A-Z]{0,2})") {
                set $block_common_exploits 1;
        }
        if ($query_string ~ "_REQUEST(=|[|\%[0-9A-Z]{0,2})") {
                set $block_common_exploits 1;
        }
        if ($query_string ~ "proc/self/environ") {
                set $block_common_exploits 1;
        }
        if ($query_string ~ "mosConfig_[a-zA-Z_]{1,21}(=|\%3D)") {
                set $block_common_exploits 1;
        }
        if ($query_string ~ "base64_(en|de)code\(.*\)") {
                set $block_common_exploits 1;
        }
        if ($block_common_exploits = 1) {
                return 403;
        }
        fastcgi_buffer_size 8192;
        ## Try all locations and relay to index.php as a fallback.
        location / {
                ## Disallow any usage of piwik assets if referer is non valid.
                location ~* ^.+\.(?:css|gif|jpe?g|js|png|swf)$ {
                        ## Defining the valid referers.
                        #valid_referers none blocked *.mysite.com othersite.com;
                        #if ($invalid_referer) {
                        #    return 444;
                        #}
                        expires max;
                        access_log off;
                        log_not_found off;
                }
                ## Redirect to the root if attempting to access a txt file.
                location ~* (?:DESIGN|(?:gpl|README|LICENSE)[^.]*|LEGALNOTICE)(?:\.txt)*$ {
                    return 404;
                }
                ## Disallow access to several helper files.
                #location ~* \.(?:bat|html?|git|ini|sh|svn[^.]*|txt|tpl|xml)$ {
                #    return 404;
                #}
                ## Supression de html dans la condition du a un soucis de chargement des vues.
                location ~* \.(?:bat|git|ini|sh|svn[^.]*|txt|tpl|xml)$ {
                    return 404;
                }
                try_files $uri /index.php?$query_string;
        }
        ## Support for favicon. Return a 1x1 transparent GIF it it doesn't
        ## exist. doesn't exist.
        location = /favicon.ico {
                try_files /favicon.ico @empty;
        }
        location @empty {
                empty_gif;
        }
        ## Relay all index.php requests to fastcgi.
        location = /index.php {
                fastcgi_cache nginx;
                fastcgi_cache_key $host$request_uri;
                fastcgi_cache_valid 200 301 5m;
                fastcgi_cache_valid 302 3m;
                fastcgi_cache_valid 404 1m;
                fastcgi_pass unix:/var/run/php5-fpm.sock;
                include fastcgi_params;
                fastcgi_param GEOIP_ADDR $remote_addr;
                fastcgi_param GEOIP_COUNTRY_CODE $geoip_country_code;
                fastcgi_param GEOIP_COUNTRY_NAME $geoip_country_name;
                fastcgi_param GEOIP_REGION $geoip_region;
                fastcgi_param GEOIP_REGION_NAME $geoip_region_name;
                fastcgi_param GEOIP_CITY $geoip_city;
                fastcgi_param GEOIP_AREA_CODE $geoip_area_code;
                fastcgi_param GEOIP_LATITUDE $geoip_latitude;
                fastcgi_param GEOIP_LONGITUDE $geoip_longitude;
                fastcgi_param GEOIP_POSTAL_CODE $geoip_postal_code;
        }
        ## Relay all piwik.php requests to fastcgi.
        location = /piwik.php {
                fastcgi_cache nginx;
                fastcgi_cache_key $host$request_uri;
                fastcgi_cache_valid 200 301 5m;
                fastcgi_cache_valid 302 3m;
                fastcgi_cache_valid 404 1m;
                fastcgi_pass unix:/var/run/php5-fpm.sock;
                include fastcgi_params;

                fastcgi_param GEOIP_ADDR $remote_addr;
                fastcgi_param GEOIP_COUNTRY_CODE $geoip_country_code;
                fastcgi_param GEOIP_COUNTRY_NAME $geoip_country_name;
                fastcgi_param GEOIP_REGION $geoip_region;
                fastcgi_param GEOIP_REGION_NAME $geoip_region_name;
                fastcgi_param GEOIP_CITY $geoip_city;
                fastcgi_param GEOIP_AREA_CODE $geoip_area_code;
                fastcgi_param GEOIP_LATITUDE $geoip_latitude;
                fastcgi_param GEOIP_LONGITUDE $geoip_longitude;
                fastcgi_param GEOIP_POSTAL_CODE $geoip_postal_code;
        }
        ## Any other attempt to access PHP files returns a 404.
        location ~* ^.+\.php$ {
                return 404;
        }
        ## No crawling of this site for bots that obey robots.txt.
        location = /robots.txt {
                return 200 "User-agent: *\nDisallow: /\n";
        }
} # server