Oven and subtypes (stills et cetera) cannot be unwrenched when power is off

Created by: Probe1

https://github.com/d3athrow/vgstation13/pull/9290

All that comes up is the return

   to_chat(user, "<span class='warning'> The powers off, it's no good. </span>")
        return

I should have tested it better and caught it. Stills are children of what I fixed.