MDEV-32361 mariadb-backup --move-back leaves out ib_logfile0

copy_back(): Also copy the dummy empty ib_logfile0 so that
MariaDB Server 10.8 or later can be started after
--copy-back or --move-back.

Thanks to Daniel Black for reporting this.

This is a 10.5 version of
commit ebf36492

extra/mariabackup/backup_copy.cc

@@ -1983,7 +1983,9 @@ copy_back()
 		snprintf(filename, sizeof filename, "%s/%s101", dst_dir,
 			 LOG_FILE_NAME_PREFIX);
 		unlink(filename);
-	} else if (!(ret = copy_or_move_file(ds_tmp, LOG_FILE_NAME, LOG_FILE_NAME,
+	}
+
+	if (!(ret = copy_or_move_file(ds_tmp, LOG_FILE_NAME, LOG_FILE_NAME,
 				      dst_dir, 1))) {
 		goto cleanup;
 	}