[python] Fix 9P muxing deadlock.
[python] Fix 9P muxing deadlock.

sunaku/wmii,bwhmather/wmii,0intro/wmii,bwhmather/wmii,0intro/wmii,sunaku/wmii,sunaku/wmii,bwhmather/wmii,bwhmather/wmii,sunaku/wmii,bwhmather/wmii,sunaku/wmii,0intro/wmii,0intro/wmii