disable warnings when evaling setup files

In particular, perl warns if a qw{} contains a #, but openids can.

If the setup file has 'use warnings', it will turn warning messages back
on, so it seems reasonable to squelch them by default.

IkiWiki/Setup.pm

@@ -33,6 +33,7 @@ sub load ($;$) {
 		if ($1) {
 			error sprintf(gettext("cannot load %s in safe mode"), $file)
 				if $safemode;
+			no warnings;
 			eval IkiWiki::possibly_foolish_untaint($content);
 			error("$file: ".$@) if $@;
 		}