Update submodules: plugins (new commits)

plugins:
    8323b53 Chris Smith <chris@dmdirc.com>
            Tidy up the channel list modes pane.

            Gerrit: http://gerrit.dmdirc.com/3133

Change-Id: If0ab119b36036c33ae1e0c491602cf1049411b2f
Update submodules: plugins (new commits)

plugins:
    182f2fb Greg Holmes <greg@dmdirc.com>
            Tidy up some warnings in PMD

            Gerrit: http://gerrit.dmdirc.com/3134

Change-Id: Ifcb320ba01d8ff1417a4ec6ca2e699984efb6305