Fixed Facebook icon /still/ causes mixed-content warning

[Snoozero]

This bug was never fixed:
http://xenforo.com/community/threads/facebook-icon-causes-mixed-content-warning.21943/

The image source was changed in 1.1 to //static.ak.fbcdn.net/images/connect_sprite.png , which throws an cert mismatch if accessed over https.
The correct URL is //www.facebook.com/images/connect_sprite.png .

 

[Scott]

Can also use https://b.s-static.ak.facebook.com/images/connect_sprite.png

 

[Kier]

Changed to use Scott's suggested URL