I tried this today and it worked perfectly – replacing all https:// calls with https:// in phpFlickr.php, and editing the lines that gflaig noted:
26, 27, 28 for direct references to https://api.flickr.com/..
and
205 for a programmatically created request
and
361 , 363 for https://farm…
as well as
604 for https://www.flickr.
Thanks to all for helping to get this fixed.
(I’m running WP 3.8.2 on Pair Networks)