FindLIBOPENJPEG.cmake: Add CheckCXXSourceCompiles

Since we use check_cxx_source_compiles
diff --git a/cmake/modules/FindLIBOPENJPEG.cmake b/cmake/modules/FindLIBOPENJPEG.cmake
index 8a49193..e2fccf3 100644
--- a/cmake/modules/FindLIBOPENJPEG.cmake
+++ b/cmake/modules/FindLIBOPENJPEG.cmake
@@ -35,6 +35,8 @@
     find_library(LIBOPENJPEG_LIBRARIES openjpeg)
     if(LIBOPENJPEG_INCLUDE_DIR AND LIBOPENJPEG_LIBRARIES)
 
+      include(CheckCXXSourceCompiles)
+
       set(CMAKE_REQUIRED_INCLUDES ${LIBOPENJPEG_INCLUDE_DIR})
       set(CMAKE_REQUIRED_LIBRARIES ${LIBOPENJPEG_LIBRARIES})