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.
adding base
foo/renamed
renamed
bar/renamed
renamed
baz
.hg/patches/baz
% test patch being renamed before committed