Main, MariaDB & Deb11; CMS:Backend

Main, MariaDB:
Switched form MariaDB back to MySQL since it is available for Deb11

Main, Debian 11
Enabled Debian 11  support, and removed warnings

CMS:Backend increased limits
PHP: post_max to 256M
Nginx: client_max_body to 256m and fcgi_timeout to 10 minutes

CMS/Backend/nginx-siteBackend-unconfigured

@@ -24,12 +24,14 @@ location = /backend/netdata {
     location /backend/database {
         deny all; #enables/disables PHPMyadmin
         index index.php index.html;
+        client_max_body_size 256m;
         alias /usr/share/phpmyadmin;
         location ~ \.php$ {
             include fastcgi_params;
             fastcgi_param SCRIPT_FILENAME $request_filename;
             fastcgi_split_path_info ^(.+\.php)(/.+)$;
             fastcgi_pass unix:/var/run/php/phpPHPver-fpm-Backend.sock;
+            fastcgi_read_timeout 10m;
             fastcgi_index index.php;
         }
     }