Force ivy bump.

Change-Id: I8608be6d035c9d7deeca526047f3f60c11111e6d
Reviewed-on: http://gerrit.dmdirc.com/3050
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>
Update submodules: plugins (new commits)

plugins:
    0504eb8 Chris Smith <chris@dmdirc.com>
            Force ivy bump, and fix ivy sources.

            Gerrit: http://gerrit.dmdirc.com/3051

Change-Id: Icbde9a9656b6772cb5f3ceac76cbdaf4ab0e0b14