parsing fails when regexp encounters a character group with ()

[gooh]

The parser cannot parse rewrite rules defining () in a character group.

Example:

rewrite ^/d/([A-Za-z0-9-,():!½$@*°'"—%]+)/([A-Za-z0-9-]+)/([A-Za-z0-9-]+)/([A-Za-z0-9-]+)/?$ /d?displayName=$1&module=$2&id=$3&visibility=$4;

Changing () to )( works around this issue.