socket-unix.cxx: Merge revision 879 from PRODUCTION_1_0_x.
socket-unix.cxx: Merge revision 879 from PRODUCTION_1_0_x.

r879:

socket-unix.cxx: Use of ghbn_mutex only in threaded builds.

hunter-packages/log4cplus,hunter-packages/log4cplus,csuideal/log4cplus,ccpaging/log4cplus,ccpaging/log4cplus,csuideal/log4cplus,hunter-packages/log4cplus,ccpaging/log4cplus,hunter-packages/log4cplus,csuideal/log4cplus,csuideal/log4cplus,ccpaging/log4cplus