Fixed the entry for WLListHeaderSegment.cpp in the appropriate Makefile.
Fixed the entry for WLListHeaderSegment.cpp in the appropriate Makefile.

ruleless/CEGUI,OpenTechEngine/CEGUI,ruleless/CEGUI,OpenTechEngine/CEGUI,OpenTechEngine/CEGUI,ruleless/CEGUI,ruleless/CEGUI,OpenTechEngine/CEGUI