message: Fix internal-only include dir for libxml2
diff: @@ -344,7 +344,7 @@ if (APPLE)
  ${SECURITY_LIBRARY}
  ${DEBUG_SYMBOLS_LIBRARY})
  - include_directories(AFTER /usr/include/libxml2)
  + include_directories(AFTER "${CMAKE_OSX_SYSROOT}/usr/include/libxml2")
  else()
  if (LIBXML2_FOUND)
  add_definitions( -DLIBXML2_DEFINED )
  