Duke3D: OOZ and OOZ2 can no longer be used as pseudo-elevators

Originally reported here: https://forums.duke4.net/topic/11315-r9028-r9206-map-alien-processor-7x-100/

Prior to 8caac903 the sprites OOZ (2300) and OOZ2 (2309) could be "ridden" like a pseudo-elevator, or like a ladder. By jumping on them the player would rise upwards, and by crouching he would be lowered, possibly reaching areas he couldn't otherwise. Starting with 8caac903 (aka. the dumpster fire fix) this is no longer possible.

At least one known usage of this trick is present in Zaxtor's Alien Processor 7X-100 map, where it was used as a gimmick elevator to get to an essential switch. I'm sure there are more instances of this out in the wild, for example using invisible variants of these sprites.

Example Map to demonstrate: oozglitch.map