Admin/logging page can be disabled and cannot be re-enabled

[jiml8]

Steps to reproduce

1. go to admin/logging page
2. uncheck all options for logging
3. observe page become blank except for top bar and message "No server logs
   Everything is working fine"

Expected behaviour

Tell us what should happen
Page should become blank, and the message is OK. However the checkboxes to re-enable various degrees of logging should be available.

Server configuration

Operating system:
Nas4Free (FreeBSD 11)

Web server:
litghttpd
Database:
sqlite
PHP version:
7.something
Nextcloud version: (see Nextcloud admin page)

Updated from an older Nextcloud/ownCloud or fresh install:
problem started on upgrade from Nextcloud 10 to Nextcloud 11.0.0 and persists after upgrade to 11.0.1
Where did you install Nextcloud from:
Nextcloud site

[MorrisJobke]

cc @icewind1991

[icewind1991]

Already fixed with nextcloud/logreader@c77ee81