MDEV-8974: boostrap systemd service for galera is confusing

Fix the conditions for systemd scripts with '@' in path.

support-files/CMakeLists.txt

@@ -79,16 +79,23 @@ IF(UNIX)
   IF(HAVE_SYSTEMD)
     CONFIGURE_FILE(mariadb.service.in
                    ${CMAKE_CURRENT_BINARY_DIR}/mariadb.service @ONLY)
-    IF(NOT RPM)
+    INSTALL(FILES use_galera_new_cluster.conf
+            ${CMAKE_CURRENT_BINARY_DIR}/mariadb.service
+            DESTINATION ${inst_location}/systemd COMPONENT SupportFiles)
+
+    # @ in directory name broken between CMake version 2.8.12.2 and 3.3
+    # http://public.kitware.com/Bug/view.php?id=14782
+    IF(NOT CMAKE_VERSION VERSION_LESS 3.3.0 OR NOT RPM)
       CONFIGURE_FILE(mariadb@.service.in
                      ${CMAKE_CURRENT_BINARY_DIR}/mariadb@.service @ONLY)
-      INSTALL(FILES use_galera_new_cluster.conf
-              ${CMAKE_CURRENT_BINARY_DIR}/mariadb.service
-              ${CMAKE_CURRENT_BINARY_DIR}/mariadb@.service
+      INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/mariadb@.service
               DESTINATION ${inst_location}/systemd COMPONENT SupportFiles)
     ENDIF()
+
     IF(INSTALL_SYSTEMD_UNITDIR)
-      # @ in directory name broken between CMake version 2.8.12.2 and 3.3
+      INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/mariadb.service
+              DESTINATION ${INSTALL_SYSTEMD_UNITDIR} COMPONENT Server)
+
       # http://public.kitware.com/Bug/view.php?id=14782
       IF(NOT CMAKE_VERSION VERSION_LESS 3.3.0 OR NOT RPM)
         INSTALL(FILES use_galera_new_cluster.conf
@@ -99,8 +106,6 @@ IF(UNIX)
                 DESTINATION ${INSTALL_SYSTEMD_UNITDIR} COMPONENT Server)
       ENDIF()
 
-      INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/mariadb.service
-              DESTINATION ${INSTALL_SYSTEMD_UNITDIR} COMPONENT Server)
     ENDIF()
   ENDIF()