Fix group restriction regression

[MorrisJobke]

• use the group restriction feature
• before: after refresh it was reset (as in "never saved")
• after: the group restriction for apps works again
• fixes Group restriction are not saved #4952

I also fixed the "never use one ID multiple times on a page". I will also create a backport to stable12.

[mention-bot]

@MorrisJobke, thanks for your PR! By analyzing the history of the files in this pull request, we identified @juliushaertl, @nickvergessen and @LukasReschke to be potential reviewers.

[MorrisJobke]

@nursoda Could I ask you to test this?

[MorrisJobke]

Backport for 12 is in #4973

[nursoda]

@MorrisJobke, is it OK to wait for the daily to be built? When is it built / what time tomorrow shall I test? I'm not a dev and I would rather use the updater app with the daily channel instead of git and build myself. Will I be able to switch back to beta channel and receive b5 once ready?

[MorrisJobke]

@nursoda You can also apply the patch by doing this:

cd /tmp
wget https://github.com/nextcloud/server/pull/4972.patch
cd /var/www/nextcloud
patch -p1 < /tmp/4972.patch

[nursoda]

Did that, works for me as expected / as it should. Thanks, that was quick :-)
NC12RC2 seems to have that fixed already, too. Great. Other oddities with RC2, though.