Pather.useWaypoint: ensure a waypoint menu is opened if "check" is "true"

When two or more characters are trying to get a waypoint simultaneously and "check" is "true", some may fail to get menu opened, hence, interact directly. D2GS derivatives treat such a behavior as a cheat and block the action (see below*). For an instance, Rubattle.net is the case (a lifetime ban guaranteed).

*D2GS output: 
2014/11/1 23:40:32.140 [cheat] minx-nec(*minx-nec)@Hcs9: packet data dump: 49120000006b000000