MDEV-7987 Fatal error: Please read "Security" section of the manual to find...

MDEV-7987 Fatal error: Please read "Security" section of the manual to find out how to run mysqld as root!

update the error message to refer to the knowledge base
that (now) has an article about this use case

sql/mysqld.cc

@@ -2031,7 +2031,8 @@ static struct passwd *check_user(const char *user)
   {
     if (!opt_bootstrap && !opt_help)
     {
-      sql_print_error("Fatal error: Please read \"Security\" section of the manual to find out how to run mysqld as root!\n");
+      sql_print_error("Fatal error: Please consult the Knowledge Base "
+                      "to find out how to run mysqld as root!\n");
       unireg_abort(1);
     }
     return NULL;