Use Connection in InviteListener

Change-Id: Ib42aeb25d72b5412ad98fe80bd6726896d423504
Depends-On: I686fa90b81cb8af49ec7a0f7d7f390825b0fe51e
Reviewed-on: http://gerrit.dmdirc.com/3435
Reviewed-by: Greg Holmes <greg@dmdirc.com>
Automatic-Compile: DMDirc Build Manager
Update submodules: plugins (new commits)

plugins:
    eaddf0d Chris Smith <chris@dmdirc.com>
            Use Connection.

            Depends-On: Ib42aeb25d72b5412ad98fe80bd6726896d423504
            Gerrit: http://gerrit.dmdirc.com/3434

    17cdd37 Chris Smith <chris@dmdirc.com>
            Use Connection in preference to Server.

            Depends-On: I56c9a2bb9ad06e9e3ad911914b29a046959e30ea
            Gerrit: http://gerrit.dmdirc.com/3432

Change-Id: Ie7d6ad5aafde72549ee01f788509da8331cfb7c5