Remove stand-alone check if user is a calendar_manager

This check needs to be performed linked with the check that the user is
or not a manager of that meeting. Otherwise, manager of the meeting that
are not calendar manager cannot edit their meetings anymore.
This is embarrassing...
Fix the unit-tests for who is allowed to edit meeting

Meeting #1 is managed by pingou so he should be allowed to edit it while
meeting #3 is managed by pingou23h so pingou is not allowed to edit it.
In addition, the redirect changed, so the tests needed adjustment.
Merge pull request #113 from fedora-infra/fix_edit

Remove stand-alone check if user is a calendar_manager