Flickr API rejects calls made via flickrlib.php methods

There seems to have been a recent change to the Flickr API that means it rejects calls that include Bot in the User-agent header.

Since calls made via flickrlib.php use the default Moodle User-agent which includes Bot they all fail.

Steps to reproduce

1. Enable and configure the Flickr public repository (Site Admin > Plugins > Repositories)
2. Navigate to a course
3. Create a label in the text insert an image
4. Open the Flickr public repository
5. Enter "fish" as the Full text and then press Search

Expected outcome

Some images are displayed for selection

Actual outcome

No images are displayed

I expect it will mean that no Flickr calls from Moodle will work.