muc/subject.py: explain why I use 12 rooms (fd.o#21152 will fix this)
muc/subject.py: explain why I use 12 rooms (fd.o#21152 will fix this)

Ziemin/telepathy-gabble,mlundblad/telepathy-gabble,mlundblad/telepathy-gabble,jku/telepathy-gabble,mlundblad/telepathy-gabble,Ziemin/telepathy-gabble,jku/telepathy-gabble,Ziemin/telepathy-gabble,jku/telepathy-gabble,Ziemin/telepathy-gabble