convert: remove restriction on multiple --rev in hg source
Multiple --rev args on convert is a new feature, and was initially disabled for
all sources. It has since been enabled on git sources, and this patch enables it
on mercurial sources.
#require execbit
$ hg init repo
$ cd repo
$ echo foo > foo
$ chmod 644 foo
$ hg ci -qAm '644'
$ chmod 755 foo
$ hg ci -qAm '755'
reverting to rev 0
$ hg revert -a -r 0
reverting foo
$ hg st
M foo
$ hg diff --git
diff --git a/foo b/foo
old mode 100755
new mode 100644
$ cd ..