Update submodules: plugins (new commits)

plugins:
    b66576e Greg Holmes <greg@dmdirc.com>
            Rewrite profile manager dialog.

            This removes the need for cinch, so also removes the related code,
            this also lays the foundation for adding a binding framework in
            the future.

            Fixes-Issue: CLIENT-422
            Gerrit: http://gerrit.dmdirc.com/3086

Change-Id: I54b5c292810e59dc7c7dee4c8e21f421fa8d79e2