Make DummyController non final for testing

Change-Id: I4501509b9f33742a5a2f5d9d6f4608432dde2eba
Reviewed-on: http://gerrit.dmdirc.com/2593
Reviewed-by: Shane Mc Cormack <shane@dmdirc.com>
Automatic-Compile: DMDirc Build Manager

src/com/dmdirc/addons/ui_dummy/DummyController.java

@@ -36,7 +36,7 @@ import java.net.URI;
 /**
  * Implements a dummy UI controller.
  */
-public final class DummyController extends BasePlugin implements UIController {
+public class DummyController extends BasePlugin implements UIController {
 
     /** The main that owns us. */
     private final Main main;