Variable exceeded

A Warning is triggerd on large boards when modifying permissions while selecting all boards.
Considering this is a PHP configuration issue (" Warning: Unknown: Input variables exceeded 1000. To increase the limit change max_input_vars in php.ini. in Unknown on line 0 "), it could be possible to consider a json-based response to bypass this problem.

As of, one could argue that this problem would only occurs on mutualised, while large boards should have access to a proper configuration file, hence the minor bug classification.
Default conf value is 1k variable