[CMake][bugfix] install OverloadCompilerFlags.cmake

(cherry picked from commit f6ab9f0f)
Signed-off-by: Carsten Gräser <graeser@dune-project.org>

cmake/modules/CMakeLists.txt

@@ -30,6 +30,7 @@ set(modules
   FindUMFPack.cmake
   Headercheck.cmake
   LanguageSupport.cmake
+  OverloadCompilerFlags.cmake
   UseInkscape.cmake
   UseLATEX.cmake)
 set(test_programs CheckForPthreads.c)