Fixed 2.6 DeprecationWarning with sha module.

friends/models.py

@@ -1,13 +1,13 @@
 import datetime
 from random import random
-import sha
 
 from django.db import models
 
 from django.template.loader import render_to_string
 from django.core.urlresolvers import reverse
 from django.contrib.auth.models import User
 from django.contrib.sites.models import Site
+from django.utils.hashcompat import sha_constructor
 
 from django.db.models import signals
 
@@ -101,8 +101,8 @@ class JoinInvitationManager(models.Manager):
 
     def send_invitation(self, from_user, to_email, message):
         contact, created = Contact.objects.get_or_create(email=to_email, user=from_user)
-        salt = sha.new(str(random())).hexdigest()[:5]
-        confirmation_key = sha.new(salt + to_email).hexdigest()
+        salt = sha_constructor.new(str(random())).hexdigest()[:5]
+        confirmation_key = sha_constructor.new(salt + to_email).hexdigest()
         accept_url = u"http://%s%s" % (
             unicode(Site.objects.get_current()),
             reverse("friends_accept_join", args=(confirmation_key,)),