Rewrite assertions to remove dead code (#1339)

Author: alex

tests/test_ssl.py

@@ -1790,8 +1790,7 @@ def replacement(connection):  # pragma: no cover
         callback = tracker()
         if callback is not None:
             referrers = get_referrers(callback)
-            if len(referrers) > 1:  # pragma: nocover
-                pytest.fail(f"Some references remain: {referrers!r}")
+            assert len(referrers) == 1
 
     def test_no_servername(self):
         """
@@ -2719,8 +2718,7 @@ def callback(conn, cert, errnum, depth, ok):  # pragma: no cover
         callback = tracker()
         if callback is not None:  # pragma: nocover
             referrers = get_referrers(callback)
-            if len(referrers) > 1:
-                pytest.fail(f"Some references remain: {referrers!r}")
+            assert len(referrers) == 1
 
     def test_get_session_unconnected(self):
         """