Use Connection in preference to Server.

Change-Id: I6140df0bb0cbcfa1740d66eb797d393692a674de
Depends-On: I56c9a2bb9ad06e9e3ad911914b29a046959e30ea
Reviewed-on: http://gerrit.dmdirc.com/3432
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>