convert: raise Abort instead of NoRepo when CVS pserver auth fails.
At this point we know the source is CVS, so we should not go through
the rest of the converters.
error: pretxncommit.nocommits hook failed: no commits allowed
transaction abort!
rollback completed
abort: no commits allowed
error: pretxncommit.nocommits hook failed: no commits allowed
transaction abort!
rollback completed
abort: no commits allowed