Update plugins after core Server changes.

Change-Id: I3fff818d6e6694163660a36f47d60271d8f0e68e
Depends-On: I9842c20b4e4ff846c9bbf4858da794a843c3b053
Reviewed-on: http://gerrit.dmdirc.com/2658
Reviewed-by: Greg Holmes <greg@dmdirc.com>
Automatic-Compile: DMDirc Build Manager