gems: update webrick to version 1.6.1
gems: update webrick to version 1.6.1

- explicitly use webrick gem version with patch against CVE-2020-25613
- https://www.ruby-lang.org/en/news/2020/09/29/http-request-smuggling-cve-2020-25613/

cmur2/openvpn-status-web,cmur2/openvpn-status-web