Update submodules: plugins (new commits)

plugins:
    d137347 Greg Holmes <greg@dmdirc.com>
            Remove some controllers.

            Also close CSD when channel closes as with SSD to prevent NPEs.

            Gerrit: http://gerrit.dmdirc.com/3292

Change-Id: If2e8ccb930c03210750133ca7afd8b8389773434