Uncessary switch_to_blog for button

[Rahe]

Hello,

On multisite, whn calling get_favorites_button, the plugin calls the switch_to_blog function even if we already are on the right site.
This triggers the switch_blog hook that many plugins are using for background processes (crons, license etc.)

This could be a great enhancement to check if the curent blog_id is the same as the desired id and remove an expensive function call.

Nicolas