bpo-35035: Rename email.utils documentation to email.utils.rst (GH-10023)

I'll watch for 404 on the old URL and will setup an HTTP redirection if needed.

Doc/library/email.rst

@@ -126,7 +126,7 @@ Legacy API:
    email.header.rst
    email.charset.rst
    email.encoders.rst
-   email.util.rst
+   email.utils.rst
    email.iterators.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``.