rfe: installer should update default php settings
The installer should be able to reset the default php settings according to the current OS (or according to /etc/alternatives/, whatever it does now for new installations should work). It could either do that unconditionally or prompt for whether default php settings should be reset or not.
This seems necessary for consistency and it eases OS updates (like https://www.howtoforge.com/community/threads/after-upgrade-to-ubuntu-18-04-01-all-websites-get-502.80746/page-2#post-383683 and I have had the same issue on debian updates from php 5.6 -> 7.x).