GIT_SILENT Fix ECM warning: use CMakePackageConfigHelpers instead of ECM variant

CMakeLists.txt

@@ -40,9 +40,9 @@ endif()
 # create a Config.cmake and a ConfigVersion.cmake file and install them
 set(CMAKECONFIG_INSTALL_DIR "${KDE_INSTALL_CMAKEPACKAGEDIR}/KF5ItemModels")
 
-include(ECMPackageConfigHelpers)
+include(CMakePackageConfigHelpers)
 
-ecm_configure_package_config_file(
+configure_package_config_file(
   "${CMAKE_CURRENT_SOURCE_DIR}/KF5ItemModelsConfig.cmake.in"
   "${CMAKE_CURRENT_BINARY_DIR}/KF5ItemModelsConfig.cmake"
   INSTALL_DESTINATION  ${CMAKECONFIG_INSTALL_DIR}