Fixed pod error while bot using it

This was spamming my server console while bot was sitting in seat.
````
[ERROR] addons/wire/lua/entities/gmod_wire_adv_pod/init.lua:358: attempt to index field 'keystate' (a nil value)
  1. unknown - addons/wire/lua/entities/gmod_wire_adv_pod/init.lua:358
````