pythonshare: release locks before deleting closed connections
pythonshare: release locks before deleting closed connections

Fixes leaving threads behind on busy hubs where many clients
queue to communicate with the same remote namespace.

mixu-/fMBT,01org/fMBT,01org/fMBT,mixu-/fMBT,mixu-/fMBT,01org/fMBT,mixu-/fMBT,01org/fMBT,mixu-/fMBT,01org/fMBT