Do not call effectiveSend if there is nothing to send.
Do not call effectiveSend if there is nothing to send.

	* src/liburbi/uabstractclient.cc (endPack): Here.

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