Improve performance of inline status spinner

Now that HandleRender no longer does an implicit Render(), we can use it inside
OnUIThreadContentOnly to save performance, on the assumption that rerendering a
view that contains an inline spinner never changes the layout.

pkg/gui/controllers/helpers/inline_status_helper.go

@@ -149,7 +149,7 @@ func (self *InlineStatusHelper) stop(opts InlineStatusOpts) {
 }
 
 func (self *InlineStatusHelper) renderContext(contextKey types.ContextKey) {
-	self.c.OnUIThread(func() error {
+	self.c.OnUIThreadContentOnly(func() error {
 		self.c.ContextForKey(contextKey).HandleRender()
 		return nil
 	})