Remove argument from cmake command finalize_dune_project

The argument to finalize_dune_project is not needed any more. This MR removes it and thus removes also the corresponding warning message.

CMakeLists.txt

@@ -39,4 +39,4 @@ if( DUNE_ENABLE_PYTHONBINDINGS )
 endif()
 
 # finalize the dune project, e.g. generating config.h etc.
-finalize_dune_project(GENERATE_CONFIG_H_CMAKE)
+finalize_dune_project()