tests: update relnotes test for actual output
I'm unclear why I didn't see this before but I consistently see it
now. In any event, it doesn't appear to be a regression, so let's just
bake it into the test.
Differential Revision: https://phab.mercurial-scm.org/D4463
--- a/tests/test-contrib-relnotes.t Tue Sep 04 17:57:49 2018 +0300
+++ b/tests/test-contrib-relnotes.t Tue Sep 04 12:36:33 2018 -0400
@@ -3,6 +3,7 @@
$ cd $TESTDIR/..
$ python3 contrib/relnotes 4.4 --stoprev 4.5
+ changeset 3398603c5621: unexpected block in release notes directive feature
New Features
============