[cmake][cleanup] format message as status message

cmake/modules/DuneCommonMacros.cmake

@@ -41,7 +41,7 @@ include(AddParMETISFlags)
 set(MINIMUM_VC_VERSION)
 if((CMAKE_CXX_COMPILER_ID STREQUAL Clang) AND
     (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 7))
-  message("Raising minimum acceptable Vc version to 1.4.1 due to use of Clang 7 (or later), see https://gitlab.dune-project.org/core/dune-common/issues/132")
+  message(STATUS "Raising minimum acceptable Vc version to 1.4.1 due to use of Clang 7 (or later), see https://gitlab.dune-project.org/core/dune-common/issues/132")
   set(MINIMUM_VC_VERSION 1.4.1)
 endif()
 find_package(Vc ${MINIMUM_VC_VERSION} NO_MODULE)