[2.7] bpo-35035: Rename email.utils documentation to email.utils.rst (GH-10023) (GH-10667)

https://bugs.python.org/issue35035

Doc/library/email.rst

@@ -61,7 +61,7 @@ Contents of the :mod:`email` package documentation:
    email.charset.rst
    email.encoders.rst
    email.errors.rst
-   email.util.rst
+   email.utils.rst
    email.iterators.rst
    email-examples.rst
 

Misc/NEWS.d/next/Documentation/2018-10-21-02-20-36.bpo-35035.4zBObK.rst

+Rename documentation for :mod:`email.utils` to ``email.utils.rst``.