nginx config: rewrite for config legacy support

see: nextcloud/documentation#2197 (comment)

Author: jngrb

nginx/nextcloud.conf.template

@@ -121,6 +121,9 @@ server {
     # then Nginx will encounter an infinite rewriting loop when it prepends `/index.php`
     # to the URI, resulting in a HTTP 500 error response.
     location ~ \.php(?:$|/) {
+        # Required for legacy support, see
+        # https://github.com/nextcloud/documentation/pull/2197#issuecomment-721432337
+        rewrite ^/(?!index|remote|public|cron|core\/ajax\/update|status|ocs\/v[12]|updater\/.+|oc[ms]-provider\/.+|.+\/richdocumentscode\/proxy) /index.php$request_uri;
 
         set $cors '';
         if ($http_origin ~ '$ALLOWED_CORS_ORIGINS') {