httprepo: suppress the `real URL is...' message in safe, common cases.
When the actual and requested URL only differ by trailing slashes,
there is no need to warn. As an example, this easily happens when
accessing repositories on Bitbucket over HTTP(S).
As far as I could tell, there were no existing tests for this
behaviour.
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
removing b
created new head
% should abort
abort: crosses branches (use 'hg merge' to merge or use 'hg update -C' to discard changes)
% should succeed
1 files updated, 0 files merged, 0 files removed, 0 files unresolved