bugfix: when createCall fails to create a leg, it also generated an unhandled exception

lib/http-routes/api/create-call.js

@@ -80,6 +80,7 @@ router.post('/', async(req, res) => {
             logger.error(err, 'createCall Error creating call');
             res.status(500).send('Call Failure');
             ep.destroy();
+            return;
           }
           /* ok our outbound INVITE is in flight */