Resolve "Countdown for the beginning of the game"

Closes #37 (closed)

core/src/tdt4240/netrunner/game/GameController.kt

@@ -90,6 +90,7 @@ class GameController(val game: Netrunner) {
     fun deregisterGameEvents() {
         // Note: Any registered `sock.on()`s made in this class MUST be deregistered here.
         Client.sock.off("entities")
+        Client.sock.off("counter")
 
         logger.debug("Game events deregistered")
         // Note: this is not an elegant solution. It would be better for the server to emit