test: add tests for the handling of References and In-Reply-To headers

These tests are known_broken, the following commit fixes them.

amended per

	id:87txmi1zq3.fsf@nikula.org
	id:87vc6yalo7.fsf@zancas.localnet

1 files changed, 1 insertions, 0 deletions

diff --git a/test/notmuch-test b/test/notmuch-test
index 27a144ef..a0c47d49 100755
--- a/test/notmuch-test
+++ b/test/notmuch-test
@@ -65,6 +65,7 @@ TESTS="
   hex-escaping
   parse-time-string
   search-date
+  thread-replies
 "
 TESTS=${NOTMUCH_TESTS:=$TESTS}