Committer verification does not allow tagging or branching existing unowned commits

[pavelhoral]

This issue is in the application for some time and I was hoping someone else would report and possibly fix it.... did not happen, so here am I :).

Already mentioned in https://groups.google.com/forum/#!topic/gitblit/KfieZleXc0U . If you have HEAD belonging to some user and try to tag it or create branch from it, GitBlit will reject the commit due to committer verification. However committer verification should not be performed, because the person making TAG or BRANCH is not actually creating any commit.