Fix so task name can really contain all from a-z0-9_- characters (#1488941)

Aleksander Machniak

2013-03-10 8b771646fadcde0abb27c2218a45942b95734838

 program/lib/Roundcube/rcube_plugin.php

@@ -237,7 +237,7 @@
    /**
     * Register this plugin to be responsible for a specific task
     *
     * @param string $task Task name (only characters [a-z0-9_.-] are allowed)
     * @param string $task Task name (only characters [a-z0-9_-] are allowed)
     */
    public function register_task($task)
    {