Only email sponsor when action is needed

We no longer email sponsors(hosts) if they don't need to verify any of
the information provided by their guest.

gregui/api/views/invitation.py

@@ -341,7 +341,8 @@ class InvitedGuestView(GenericAPIView):
             invite_link.expire = timezone.now()
             invite_link.save()
 
-            # Send an email to the sponsor
+        # Send an email to the sponsor if the guest needs to be verified
+        if not person.is_verified:
             confirmmailer = ConfirmGuest()
             confirmmailer.send_confirmation_mail_from_link(invite_link)
         return Response(status=status.HTTP_200_OK)