Update submodules: plugins (new commits)

plugins:
    546b149 Chris Smith <chris@dmdirc.com>
            More deprecation removal.

            Gerrit: http://gerrit.dmdirc.com/3287

Change-Id: Iff3f90c0e2424494330de634b5341a6b2b0d2a9f
Update submodules: plugins (new commits)

plugins:
    33c7bf1 Chris Smith <chris@dmdirc.com>
            Unused method.

            Gerrit: http://gerrit.dmdirc.com/3288

Change-Id: I32137810cd2ee93df8f399ef933ab0c8bed2cd00