threaded test uobject: Fix a race condition (explains threaded-auto failure).
threaded test uobject: Fix a race condition (explains threaded-auto failure).

	* src/uobjects/threaded.uob/threaded.cc (onChangeDelay): Lock
	around non-atomic list appending code.

aldebaran/urbi,urbiforge/urbi,aldebaran/urbi,urbiforge/urbi,urbiforge/urbi,urbiforge/urbi,urbiforge/urbi,aldebaran/urbi,urbiforge/urbi,aldebaran/urbi,aldebaran/urbi,aldebaran/urbi,aldebaran/urbi,aldebaran/urbi,urbiforge/urbi,urbiforge/urbi,urbiforge/urbi