closes bpo-32721: do not fail test_hashlib if _md5 isn't available (GH-5441) (GH-5442)

(cherry picked from commit 95441809)
Co-authored-by: Benjamin Peterson <benjamin@python.org>

Lib/test/test_hashlib.py

@@ -196,7 +196,7 @@ class HashLibTestCase(unittest.TestCase):
         try:
             import _md5
         except ImportError:
-            pass
+            self.skipTest("_md5 module not available")
         # This forces an ImportError for "import _md5" statements
         sys.modules['_md5'] = None
         # clear the cache

Misc/NEWS.d/next/Tests/2018-01-29-21-30-44.bpo-32721.2Bebm1.rst

+Fix test_hashlib to not fail if the _md5 module is not built.