Use settings.EXTERNAL_HOST when sending activation emails

Activation emails were using django's sites framework which always has
the domain set to zulip.com.

(imported from commit b81eae96e1a75b64dd93970760b869f3271ce88c)

confirmation/models.py

@@ -34,8 +34,7 @@ def generate_key():
     return generate_random_token(40)
 
 def generate_activation_url(key):
-    current_site = Site.objects.get_current()
-    return u'https://%s%s' % (current_site.domain,
+    return u'https://%s%s' % (settings.EXTERNAL_HOST,
             reverse('confirmation.views.confirm', kwargs={'confirmation_key': key}))
 
 

zerver/test_signup.py

@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+from django.conf import settings
 from django.test import TestCase
 
 from zilencer.models import Deployment
@@ -238,7 +239,7 @@ class LoginTest(AuthedTestCase):
         from django.core.mail import outbox
         for message in reversed(outbox):
             if email in message.to:
-                confirmation_link_pattern = re.compile("example.com(\S+)>")
+                confirmation_link_pattern = re.compile(settings.EXTERNAL_HOST + "(\S+)>")
                 confirmation_url = confirmation_link_pattern.search(
                     message.body).groups()[0]
                 break