Show rollback link on changes list only for RC_EDIT

Changing from !RC_NEW to RC_EDIT to have no rollback links, when this
method is called accidently for RC_LOG or RC_EXTERNAL (or for the old
RC_MOVE/RC_MOVE_OVER_REDIRECT). For that types there are 0 revisions to
rollback.

Change-Id: I1cbdc87a8b8e0cecf6fbfa3b3a64d5015057bccf