Type NodeJS.Timer got replaced with NodeJS.Timeout in newer TSC versions

server/src/timer.class.ts

@@ -14,7 +14,7 @@ export class Timer {
     return Timer.INSTANCE;
   }
 
-  private intervalHdl?: NodeJS.Timer;
+  private intervalHdl?: NodeJS.Timeout;
   private subscribers: {
     [id: number]: Subscriber;
   } = {};