notify: drop import required by Python 2.4

Toto, I've a feeling we're not in anno 2004 anymore.

hgext/notify.py

@@ -134,9 +134,6 b' web.baseurl'
 '''
 
 import email, socket, time
-# On python2.4 you have to import this by name or they fail to
-# load. This was not a problem on Python 2.7.
-import email.Parser
 from mercurial.i18n import _
 from mercurial import patch, cmdutil, util, mail
 import fnmatch