Fixes deadlock in OSD plugin

Change-Id: I8b978cff8b1ea0ed96585ec5fd57f09be90a29bc
Reviewed-on: http://gerrit.dmdirc.com/634
Automatic-Compile: Gregory Holmes <greg@dmdirc.com>
Reviewed-by: Gregory Holmes <greg@dmdirc.com>

src/com/dmdirc/addons/osd/OsdWindow.java

@@ -254,4 +254,9 @@ public final class OsdWindow extends JDialog implements MouseListener,
             transferFocusBackward();
         }
     }
+
+    /** {@inheritDoc} */
+    @Override  public String toString() {
+        return label.getText();
+    }
 }