[bug fix]: xml includes handled wrong

Former-commit-id: 5e403fa539ad1acafe6206495e875885cb9afd2d

shared/cmake/libigl.cmake

@@ -401,7 +401,6 @@ if(LIBIGL_WITH_XML)
   set(TINYXML2_DIR "${LIBIGL_EXTERNAL}/tinyxml2")
   if(NOT TARGET tinyxml2)
     add_library(tinyxml2 STATIC ${TINYXML2_DIR}/tinyxml2.cpp ${TINYXML2_DIR}/tinyxml2.h)
-    target_include_directories(tinyxml2 PUBLIC ${TINYXML2_DIR})
     set_target_properties(tinyxml2 PROPERTIES
             COMPILE_DEFINITIONS "TINYXML2_EXPORT"
             VERSION "3.0.0"
@@ -409,4 +408,5 @@ if(LIBIGL_WITH_XML)
   endif()
   compile_igl_module("xml")
   target_link_libraries(igl_xml ${IGL_SCOPE} tinyxml2)
+  target_include_directories(igl_xml ${IGL_SCOPE} ${TINYXML2_DIR})
 endif()