mtr: --gdb mode, also quote ";", not only " "

mysql-test/lib/My/Debugger.pm

@@ -139,7 +139,7 @@ sub do_args($$$$$) {
   my $v = $debuggers{$k};
 
   # on windows mtr args are quoted (for system), otherwise not (for exec)
-  sub quote($) { $_[0] =~ / / ? "\"$_[0]\"" : $_[0] }
+  sub quote($) { $_[0] =~ /[; ]/ ? "\"$_[0]\"" : $_[0] }
   sub unquote($) { $_[0] =~ s/^"(.*)"$/$1/; $_[0] }
   sub quote_from_mtr($) { IS_WINDOWS() ? $_[0] : quote($_[0]) }
   sub unquote_for_mtr($) { IS_WINDOWS() ? $_[0] : unquote($_[0]) }