[CentOS] firefox update extensions

  The update feature in FF appears to be disabled, which is fine since
I upgrade from the repositories. But it looks like the extension
updates are disabled as well. Even if I go to the extensions menu,
right click on update they don't seem to update.

  Is there a setting to enable extension updates? I set
extension.update.autoupdate to true in about:config and that didn't
seem to help.