improve robustness of host comparision for wss:// Origin headers

see: https://github.com/ansible/tower/issues/2647

awx/main/conf.py

@@ -101,6 +101,17 @@ register(
     category_slug='system',
 )
 
+register(
+    'WEBSOCKET_ORIGIN_WHITELIST',
+    field_class=fields.StringListField,
+    label=_('Websocket Origin Whitelist'),
+    help_text=_("If Tower is behind a reverse proxy/load balancer, use this setting "
+                "to whitelist hostnames which represent trusted Origin hostnames from which "
+                "Tower should allow websocket connections."),
+    category=_('System'),
+    category_slug='system',
+)
+
 
 def _load_default_license_from_file():
     try: