Improve web-ui and js-executor microservices gracefull shutdown

msa/js-executor/server.ts

@@ -69,7 +69,7 @@ async function createQueue(serviceType: string): Promise<IQueue> {
 }
 
 [`SIGINT`, `SIGUSR1`, `SIGUSR2`, `uncaughtException`, `SIGTERM`].forEach((eventType) => {
-    process.on(eventType, async () => {
+    process.once(eventType, async () => {
         logger.info(`${eventType} signal received`);
         await exit(0);
     })

msa/web-ui/server.ts

@@ -123,7 +123,7 @@ let connections: Socket[] = [];
 })();
 
 [`SIGINT`, `SIGUSR1`, `SIGUSR2`, `uncaughtException`, `SIGTERM`].forEach((eventType) => {
-    process.on(eventType, async () => {
+    process.once(eventType, async () => {
         logger.info(`${eventType} signal received`);
         await exit(0);
     });