fixed does not send final status call back if call canceled quickly (#1393)

* fixed callsession should cleanup resource if call was canceled while fetching app

* wip

* wip

* wip

* wip

* wip

lib/middleware.js

@@ -112,6 +112,14 @@ module.exports = function(srf, logger) {
         req.locals.callingNumber = sipURIs[1];
       }
     }
+
+    // Feature server INVITE request pipelines taking time to finish,
+    // while connecting and fetch application from db and invoking webhook.
+    // call can be canceled without any handling, so we add a listener here
+    req.once('cancel', (sipMsg) => {
+      logger.info(`${callId} got CANCEL request`);
+      req.locals.canceled = true;
+    });
     next();
   }