bug: Firing Stasis Shield or Displacertron with keyboard/joystick firing causes agents to teleport around if they're moving

[bobf5]

(issue since 1996)

In and out of key control mode, if an agent fires a Stasis Shield or Displacertron via keyboard/joystick firing while they're moving, they'll teleport around the level, similarly to #273.

stasis_displacer_teleport.webm