Image caption warning for external badges

Prerequisites An outgoing server configured (mailcacher or similar). One Badgr account on badgr.io with some badges and a collection (contact Sara if you don't have one... I created several for testing purposes and I can share them with you). Debugging for developers enabled in Moodle. Testing instructions Login as admin. Go to "Preferences / Badges / Backpack settings". Connect to the backpack using the Badgr.io account. Open the verification email and open the URL to validate the account. Confirm  status is set to Connected. In the "Badge import settings" section (in the "Backpack settings" page), select at least one collection with badges and save changes. Go to the user profile. Check  there is, at least, one badge in the "Badges from other web sites:" section. Check no warning is displayed.