CMake: Only add include directory to jsoncpp_lib target if CMake version supports the command.

Author: Gachapen

src/lib_json/CMakeLists.txt

@@ -39,9 +39,11 @@ ADD_LIBRARY( jsoncpp_lib ${JSONCPP_LIB_TYPE}
 SET_TARGET_PROPERTIES( jsoncpp_lib PROPERTIES OUTPUT_NAME jsoncpp )
 SET_TARGET_PROPERTIES( jsoncpp_lib PROPERTIES VERSION ${JSONCPP_VERSION} SOVERSION ${JSONCPP_VERSION_MAJOR} )
 
-TARGET_INCLUDE_DIRECTORIES( jsoncpp_lib
-                            PUBLIC ${JSONCPP_INCLUDE_DIR}
-                            )
+IF(CMAKE_VERSION VERSION_EQUAL 2.8.11 OR CMAKE_VERSION VERSION_GREATER 2.8.11)
+    TARGET_INCLUDE_DIRECTORIES( jsoncpp_lib
+                                PUBLIC ${JSONCPP_INCLUDE_DIR}
+                                )
+ENDIF(CMAKE_VERSION VERSION_EQUAL 2.8.11 OR CMAKE_VERSION VERSION_GREATER 2.8.11)
 
 # Install instructions for this target
 IF(JSONCPP_WITH_CMAKE_PACKAGE)