Returns ..() on Microwaves

If you want this to use power, whatever asshat commented that out broke it.
Adapting my code, figured out that this was what broke it only days after trying to locate the issue, thinking it was related to my own code.

Probably quite minor, but this is what it is supposed to be functioning like. Right now it's just some powerless machine and whatever you do on /obj/machinery/New() is not working here without it.
Merge pull request #5288 from laser50/patch-1

Returns ..() on Microwaves