Update submodules: plugins (new commits)

plugins:
    d205863 Chris Smith <chris@dmdirc.com>
            Remove deprecated method.

            Gerrit: http://gerrit.dmdirc.com/3095

    1ca6ab2 Greg Holmes <greg@dmdirc.com>
            Re-enable warnings on plugins building

            Gerrit: http://gerrit.dmdirc.com/3094

Change-Id: I7536d767106aef3ee2ede83379c638429cffe4ad