MDEV-25354: Fix my_print_defaults wording

extra/my_print_defaults.c

@@ -116,7 +116,7 @@ static void usage()
 {
   version();
   puts("This software comes with ABSOLUTELY NO WARRANTY. This is free software,\nand you are welcome to modify and redistribute it under the GPL license\n");
-  puts("Prints all arguments that is give to some program using the default files");
+  puts("Displays the options from option groups of option files, which is useful to see which options a particular tool will use");
   printf("Usage: %s [OPTIONS] [groups]\n", my_progname);
   my_print_help(my_long_options);
   my_print_default_files(config_file);