Update player firing state when left mouse button is released

PlayerWeapon.cs

  void Update()
  {
      if (player.Dead || !networkID.IsMine)
      {
          return;
      }

      if (Input.GetKeyUp(KeyCode.Alpha1))
      {
          syncPropertyAgent.Modify(CURRENT_WEAPON, 0);
      }
      else if (Input.GetKeyUp(KeyCode.Alpha2))
      {
          syncPropertyAgent.Modify(CURRENT_WEAPON, 1);
      }

      if (Input.GetButton("Fire1"))
      {
          Guns[CurrentWeapon].Fire();
      }
      else
      {
          // Update player firing state when left mouse button is released
          Guns[CurrentWeapon].StopFiring();
      }
  }