Remove `utils.parse_mailmap`

Hasn't been used since 3456b667c3

Change-Id: I454b5fcebb1cca3852155bdf850eacd84ab01980

nova/utils.py

@@ -415,18 +415,6 @@ def get_my_linklocal(interface):
         raise exception.NovaException(msg)
 
 
-def parse_mailmap(mailmap='.mailmap'):
-    mapping = {}
-    if os.path.exists(mailmap):
-        fp = open(mailmap, 'r')
-        for l in fp:
-            l = l.strip()
-            if not l.startswith('#') and ' ' in l:
-                canonical_email, alias = l.split(' ')
-                mapping[alias.lower()] = canonical_email.lower()
-    return mapping
-
-
 def str_dict_replace(s, mapping):
     for s1, s2 in mapping.iteritems():
         s = s.replace(s1, s2)