subrepo: fix cloning of repos from urls without slash after host (issue2970)
This fixes a regression introduced with the new url handling in 1.9.
This should perhaps be fixed in the url class instead, but that might be too
invasive for a stable bugfix.
http://mercurial.selenic.com/bts/issue1089
$ hg init
$ mkdir a
$ echo a > a/b
$ hg ci -Am m
adding a/b
$ hg rm a
removing a/b
$ hg ci -m m a
$ mkdir a b
$ echo a > a/b
$ hg ci -Am m
adding a/b
$ hg rm a
removing a/b
$ cd b
Relative delete:
$ hg ci -m m ../a