openvr lines are dirty by default

src/backend/openvr/lines.rs

@@ -82,6 +82,7 @@ impl LinePool {
                 width: 0.002,
                 override_width: true,
                 image_view: Some(self.view.clone()),
+                image_dirty: true,
                 ..Default::default()
             },
             ..Default::default()