Remove unused method.

Change-Id: Ie4c2dfb2da88679e367d921650dcbce87b9ba328
Depends-On: Ia70524f84070adf62dff7822ac13807eafff499f
Reviewed-on: http://gerrit.dmdirc.com/3294
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Chris Smith <chris@dmdirc.com>
Update submodules: plugins (new commits)

plugins:
    7e53c60 Greg Holmes <greg@dmdirc.com>
            Remove deprecated method calls.

            Depends-On: Ie4c2dfb2da88679e367d921650dcbce87b9ba328
            Gerrit: http://gerrit.dmdirc.com/3293

Change-Id: I77d79b4853e6e703c047716811171e661c3ec6b2