logging: restrict file log permissions

With the new file utility functions permissions can be restricted for
newly created files. For the log file specified by the -l option it
is better to remove the "other" permissions (0640) to make it similar
to the system log.

logging.c

@@ -186,7 +186,7 @@ LOG_OpenFileLog(const char *log_file)
   FILE *f;
 
   if (log_file) {
-    f = UTI_OpenFile(NULL, log_file, NULL, 'A', 0644);
+    f = UTI_OpenFile(NULL, log_file, NULL, 'A', 0640);
   } else {
     f = stderr;
   }