gitweb: fix error in sanitize when highlight is enabled

$1 becomes undef by internal regex, since it has no capture groups.

Match against accpetable control characters using index() instead of a regex.

Signed-off-by: Orgad Shaneh <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: orgads

gitweb/gitweb.perl

@@ -1538,7 +1538,7 @@ sub sanitize {
 	return undef unless defined $str;
 
 	$str = to_utf8($str);
-	$str =~ s|([[:cntrl:]])|($1 =~ /[\t\n\r]/ ? $1 : quot_cec($1))|eg;
+	$str =~ s|([[:cntrl:]])|(index("\t\n\r", $1) != -1 ? $1 : quot_cec($1))|eg;
 	return $str;
 }