Welding doesn't properly stop when the welder is dropped mid-weld

[anf3is]

Steps to reproduce

1. Start welding
2. Drop welder

Observe: welding icon even without welder in the extra slot
Expected: no icon

3. pickup welder

Observe: welder starts to weld again / focus glues to the door
Expected: no welding

Solution

Need to implement proper Drop method for welder.