Merge pull request #4008 from srinivasreddy/rm_import

remove unnecessay import

sphinx/ext/inheritance_diagram.py

@@ -39,10 +39,7 @@ r"""
 import re
 import sys
 import inspect
-try:
-    from hashlib import md5
-except ImportError:
-    from md5 import md5
+from hashlib import md5
 
 from six import text_type
 from six.moves import builtins