Removing duplicate code from mysql-test-run.pl

mysql-test/mysql-test-run.pl:
  Removing duplicate code.

mysql-test/mysql-test-run.pl

@@ -3870,14 +3870,6 @@ sub mysqld_arguments ($$$$) {
     mtr_add_arg($args, "%s--user=root");
   }
 
-  # When mysqld is run by a root user(euid is 0), it will fail
-  # to start unless we specify what user to run as, see BUG#30630
-  my $euid= $>;
-  if (!$glob_win32 and $euid == 0 and
-      (grep(/^--user/, @$extra_opt, @opt_extra_mysqld_opt)) == 0) {
-    mtr_add_arg($args, "%s--user=root", $prefix);
-  }
-
   if ( $opt_valgrind_mysqld )
   {
     mtr_add_arg($args, "%s--skip-safemalloc", $prefix);