CMake: change for execute_process and strip whitespaces

        # Get the version from last git tag plus number of additional commits:

        FIND_PACKAGE(Git QUIET)

        IF(GIT_FOUND)

            EXEC_PROGRAM(

                git ${CMAKE_CURRENT_SOURCE_DIR}

                ARGS describe --tags HEAD

            EXECUTE_PROCESS(

                COMMAND git describe --tags HEAD

                WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}

                OUTPUT_VARIABLE version

                RETURN_VALUE status)

                RESULT_VARIABLE status

                OUTPUT_STRIP_TRAILING_WHITESPACE)

            IF(status AND NOT status EQUAL 0)

                MESSAGE(STATUS "Git repository present, but could not find any tags.")

                SET(${project_version} "${${project_version}}-unknown")

            ELSE()

                STRING(REGEX REPLACE "^release-" "" version ${version})

                STRING(REGEX REPLACE "([v0-9.]+)-([0-9]+)-([A-Za-z0-9]+)" "\\1-\\2-\\3" ${project_version} ${version})

                EXEC_PROGRAM(

                    git ARGS

                    status --porcelain ${CMAKE_CURRENT_SOURCE_DIR}

                EXECUTE_PROCESS(

                    COMMAND git status --porcelain

                    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}

                    OUTPUT_VARIABLE PROJECT_STATUS)

                IF(PROJECT_STATUS STREQUAL "")

                    MESSAGE(STATUS "Git project directory is clean.")

                ELSE(PROJECT_STATUS STREQUAL "")

                ELSE()

                    MESSAGE(STATUS "Git project directory is dirty:\n ${PROJECT_STATUS}.")

                    SET(${project_version} "${${project_version}}-dirty")

                ENDIF(PROJECT_STATUS STREQUAL "")

                ENDIF()

                # Check if commit flag has been set by the CI:

                IF(DEFINED ENV{CI_COMMIT_TAG})