WordCamp images stored with http URL

[GaryJ]

When uploading images to the 2017 WordCamp London site via the normal Media page, the images are being saved with a http URL. This means that:

• images inserted into content has the http URL.
• images used for the sponsors shortcode output use http URL.

The wp-admin and the front-end, are both trying to display as https (good), but the images are creating mixed-content warnings.

We can workaround the first issue by adjusting the post content markup, but other instances such as sponsors shortcode markup (which, for us, appear in a widget on every single page) can not be worked around. This means that potential attendees are being asked to enter their ticket details on a page that isn't marked as secure.

Possibly related to #2348. The 2017 WordCamp London site was created in late 2016.

Slack discussion: ​https://wordpress.slack.com/archives/meta-wordcamp/p1486043623002014

[GaryJ]

Screenshot of media details box, showing file is stored with a http URL reference.

[iandunn]

Related #2348

[ryelle]

This is happening on the 2017 WordCamp London site because the site URL (in the database) is non-https. This should not be the case for any current sites, so closing this issue.