Make the php.ini editable over updates

[ofriedri]

Some UCS administrators have the demand to change settings in the php.ini like upload_max_filesize.

If an admin connects to the running container and changes the php settings under: /etc/php/7.2/apache2/php.ini or /etc/php/7.2/apache2/conf.d/60-nextcloud.ini then these settings aren't persistent over updates.

I described a workaround using docker volumes here https://help.univention.com/t/howto-nextcloud-raise-php-upload-max-filesize/15279, which is error-prone and complicated.

So please provide a way to overwrite the default PHP settings.

I suggest adding the 60-nextcloud.ini as an additional volume.