webadmin: cleaned up setChangeProhibitionReason calls

Cleaned up all setChangeProhibitionReason calls to use non-hardcoded
strings. Fixed some spelling mistakes in some of the calls.

Change-Id: I8002e0aa88c892475c74d264a72e0ec30fe2b7d6
Bug-Url: https://bugzilla.redhat.com/995754
Signed-off-by: Greg Sheremeta <gshereme@redhat.com>