Merge pull request #3543 from AlanCoding/migration_schmigration

Fix server error for in-flight migration

awx/main/middleware.py

@@ -127,6 +127,9 @@ class SessionTimeoutMiddleware(object):
 
     def process_response(self, request, response):
         should_skip = 'HTTP_X_WS_SESSION_QUIET' in request.META
+        # Something went wrong, such as upgrade-in-progress page
+        if not hasattr(request, 'session'):
+            return response
         # Only update the session if it hasn't been flushed by being forced to log out.
         if request.session and not request.session.is_empty() and not should_skip:
             expiry = int(settings.SESSION_COOKIE_AGE)