[PATCH 2 of 3] test-chg: run only with chg

[Yuya Nishihara]

# HG changeset patch
# User Yuya Nishihara <yuya at tcha.org>
# Date 1458511143 25200
#      Sun Mar 20 14:59:03 2016 -0700
# Node ID 369d151ba12b38708c9e8094c157a56bb52e2d1f
# Parent  346e013b362fcbb5146c6167cea35bdb14c848ec
test-chg: run only with chg

It doesn't make sense to run test-chg.t without chg, so ignore it with vanilla
hg. test-chg.t can host chg-specific tests.

diff --git a/tests/test-chg.t b/tests/test-chg.t
--- a/tests/test-chg.t
+++ b/tests/test-chg.t
@@ -1,3 +1,5 @@
+#require chg
+
 init repo
 
   $ hg init foo