PunBB 1.3.1 hotfix for a potential SQL-injections at admin users page.

hotfix_131_sql_injection_in_admin_users PunBB 1.3.1 hotfix for a potential SQL-injections at admin users page. 1.0 Fixed an potential SQL-injection at admin users page. PunBB Development Team 1.3.1 1.3.1