handle wp remove

def cmd_wp_remove(self, args):
        '''handle wp remove'''
        if len(args) != 1:
            print("usage: wp remove WPNUM")
            return
        idx = int(args[0])
        if idx < 0 or idx >= self.wploader.count():
            print("Invalid wp number %u" % idx)
            return
        wp = self.wploader.wp(idx)

        # setup for undo
        self.undo_wp = copy.copy(wp)
        self.undo_wp_idx = idx
        self.undo_type = "remove"

        self.wploader.remove(wp)
        self.fix_jumps(idx, -1)
        self.send_all_waypoints()
        print("Removed WP %u" % idx)