Point to HTTPS URL for Flickr API

Flickr API is now SSL only, as of June 27th 2014:
http://code.flickr.net/2014/04/30/flickr-api-going-ssl-only-on-june-27th-2014/

Bug: 67298
Change-Id: I79f100e64ec601a2bf5b3c18fcc9a39e0cd01c1c
Mingle: https://wikimedia.mingle.thoughtworks.com/projects/multimedia/cards/776