Fix UNKNOWN WPF status handling

Author: AlexeyMerzlyakov

nav2_waypoint_follower/src/waypoint_follower.cpp

@@ -275,9 +275,7 @@ WaypointFollower::followWaypoints()
  }
  }
 
- if (current_goal_status_.status != ActionStatus::PROCESSING &&
- current_goal_status_.status != ActionStatus::UNKNOWN)
- {
+ if (current_goal_status_.status != ActionStatus::PROCESSING) {
  // Update server state
  goal_index++;
  new_goal = true;