Update footer.yml

_data/footer.yml

@@ -1,11 +1,5 @@
 # Footer navigation links
   
-- title: GitHub page
-  url: https://github.com/duplicati/duplicati
-
-- title: Facebook page
-  url: https://facebook.com/pages/duplicati  
-  
 - title: Donate via PayPal
   url: https://www.paypal.com/cgi-bin/webscr?cmd=_xclick&business=paypal%40hexad%2edk&item_name=Duplicati%20Donation&no_shipping=2&no_note=1&tax=0&currency_code=EUR&bn=PP%2dDonationsBF&charset=UTF%2d8&lc=US