only show the unsel LD_LIBRARY_PATH option in the preferences window on Linux, since it has not affect on other platforms.
only show the unsel LD_LIBRARY_PATH option in the preferences window on Linux,
since it has not affect on other platforms.

sideeffects/HoudiniEngineForMaya,sideeffects/HoudiniEngineForMaya,sideeffects/HoudiniEngineForMaya