rhg: Colored output is not supported
Fallback if it is requested explicitly.
The default is documented as use color "whenever it seems possible".
rhg proceeds without color in that case.
Differential Revision: https://phab.mercurial-scm.org/D11762
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
$ hg init
$ echo 'base' > base
$ hg ci -Ambase
adding base
$ hg qnew -mmqbase mqbase
$ hg qsave
$ hg qrestore 2
restoring status: hg patches saved state