image/rotation: Configure adj during rotation

This was missing after we stopped configuring adjustments in snapshots.

Closes #302

src/widgets/image/rotation.rs

@@ -26,6 +26,7 @@ impl imp::LpImage {
         }
 
         self.rotation.set(rotation);
+        obj.configure_adjustments();
         obj.notify_rotation();
         obj.queue_draw();
     }