BUG: superbuild: avoid conflict with system muParser headers (WIP)

SuperBuild/CMake/External_otb.cmake

@@ -137,6 +137,9 @@ if(APPLE)
     env
     ${LDLIBVAR}=${CMAKE_INSTALL_PREFIX}/lib:$ENV{${LDLIBVAR}}
     ${CMAKE_COMMAND})
+  list(APPEND OTB_SB_CONFIG
+    -DCMAKE_C_FLAGS:STRING="-I${CMAKE_INSTALL_PREFIX}/include"
+    -DCMAKE_CXX_FLAGS:STRING="-I${CMAKE_INSTALL_PREFIX}/include")
 else()
   set(OTB_SB_CMAKE_COMMAND ${SB_CMAKE_COMMAND})
 endif()