i found that it was inside the wp-includes folder and the file is the capabilities.php file.
the piece of code that i removed was on line 1208.
here is how it looks now:
1206:function is_super_admin( $user_id = false ) {
1207: if ( ! $user_id ) {
1208: $user_id = ! empty($current_user) ? $current_user->id : 0;
1209: }
1210:
1211: if ( ! $user_id )
1212: return false;
So the code i removed was between 1207 and the current 1208 something with wp_get_user if i’m not mistaken…