Remove unused method

Depends-On: I9c0f0cc56b11844399b95a19cc855771984d03a0
Change-Id: Iddf8113511c0b8787d182e8f6d856f10beaabd84
Reviewed-on: http://gerrit.dmdirc.com/3295
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Chris Smith <chris@dmdirc.com>
Update submodules: plugins (new commits)

plugins:
    0caa76e Greg Holmes <greg@dmdirc.com>
            Remove deprecated methods.

            Depends-On: Iddf8113511c0b8787d182e8f6d856f10beaabd84
            Gerrit: http://gerrit.dmdirc.com/3296

Change-Id: I3d9e9a2a3e1692b30ff1e05dd6b1b52b1fde24ae