gmod_wire_adv_pod: clean up validity checks.
gmod_wire_adv_pod: clean up validity checks.

thegrb93/wire,NezzKryptic/Wire,immibis/wiremod,rafradek/wire,mms92/wire,garrysmodlua/wire,dvdvideo1234/wire,Grocel/wire,CaptainPRICE/wire,wiremod/wire,plinkopenguin/wiremod,notcake/wire,bigdogmat/wire,sammyt291/wire,mitterdoo/wire,Python1320/wire