[2.7] Fixed several assertTrue() that were intended to be assertEqual(). (GH-8191) (GH-8202)

Fixed also testing the "always" warning filter.
(cherry picked from commit b796e7dcdc24ff7ec53044af041254c83a8ace21)

Co-authored-by: Sergey Fedoseev <fedoseev.sergey@gmail.com>
diff --git a/Lib/test/test_warnings.py b/Lib/test/test_warnings.py
index ae081ee..a9568f6 100644
--- a/Lib/test/test_warnings.py
+++ b/Lib/test/test_warnings.py
@@ -107,10 +107,14 @@
             self.module.resetwarnings()
             self.module.filterwarnings("always", category=UserWarning)
             message = "FilterTests.test_always"
-            self.module.warn(message, UserWarning)
-            self.assertTrue(message, w[-1].message)
-            self.module.warn(message, UserWarning)
-            self.assertTrue(w[-1].message, message)
+            def f():
+                self.module.warn(message, UserWarning)
+            f()
+            self.assertEqual(len(w), 1)
+            self.assertEqual(w[-1].message.args[0], message)
+            f()
+            self.assertEqual(len(w), 2)
+            self.assertEqual(w[-1].message.args[0], message)
 
     def test_default(self):
         with original_warnings.catch_warnings(record=True,