Config feed should use HTTPS links instead of clear-text HTTP

[daltonclaybrook]

The app menu config feed (https://www.whitehouse.gov/sites/default/files/feeds/config.json) returns a JSON array of menu items, each with a corresponding link to the feed content for that item. Each of these links use HTTP even though all of these resources are accessible through HTTPS. Starting in iOS 9, apps submitted to the app store are required to use HTTPS. This feed should be updated to include HTTPS links instead.