[test/helper] Do not use deprecated method

test/helper.py

@@ -137,8 +137,8 @@ def expect_info_dict(self, expected_dict, got_dict):
 
 
 def assertRegexpMatches(self, text, regexp, msg=None):
-    if hasattr(self, 'assertRegexpMatches'):
-        return self.assertRegexpMatches(text, regexp, msg)
+    if hasattr(self, 'assertRegexp'):
+        return self.assertRegexp(text, regexp, msg)
     else:
         m = re.match(regexp, text)
         if not m: