Attach X-Call-Id to asynchronous calls

Signed-off-by: Alex Ellis (VMware) <alexellis2@gmail.com>

gateway/server.go

@@ -93,7 +93,7 @@ func main() {
 			log.Fatalln(queueErr)
 		}
 
-		faasHandlers.QueuedProxy = handlers.MakeQueuedProxy(metricsOptions, true, natsQueue)
+		faasHandlers.QueuedProxy = handlers.MakeCallIDMiddleware(handlers.MakeQueuedProxy(metricsOptions, true, natsQueue))
 		faasHandlers.AsyncReport = handlers.MakeAsyncReport(metricsOptions)
 	}