PlantUML image unencrypted http request makes website "insecure"

[UnlimitedCookies]

Describe the bug
PlantUML requests the image via unencrypted HTTP and therefore shows a warning message to the user that the site is insecure.

This is requested:

<img src="http://www.plantuml.com/plantuml/svg/U9nLZy4AWp0CXkzvYi3Ele18iKw4NJV6pg7c8DRMfN7Flpg5QGu9uV_oywTEIgBBv67ESt33J47ncLW0rew5GLjY6rzHHY2dmuUKqUAbwvfS07P7Ra5P0dbqvFs9R4d61_afXfrkIgmgTC8PkFDxuQHepFyckpPORBQxVlt1FVHye0wBtPpNo6lQm6SHQWvz_l8BXQPBk000" alt="uml diagram" class="uml-diagram">

To Reproduce
Steps to reproduce the behavior:
Go to: https://docs.requarks.io/releases
See read warning message.
Expected behavior
Shiny encrypted picture from PlantUML

[UnlimitedCookies]

This might have been solved by #1223 but the wiki.js docs website still uses an HTTP image on its release site - So there's still an issue apparently.

[NGPixel]

The fix only affects new installations. Existing installations must be fixed via the DB or wait the next release which will allow to save the rendering configuration from the admin area.

The releases page on the wiki.js docs website has been fixed.