ENH: Change http to https

[Leengit]

Addresses runtime error messages like:

Mixed Content: The page at 'https://extensions.slicer.org/catalog/All/32752/linux' was loaded over HTTPS, but requested an insecure image 'http://www.slicer.org/slicerWiki/images/2/2b/SlicerIGTLogo.png'. This content should also be served over HTTPS.

This was accomplished with a simple string replacement. What is best practice for checking that this hasn't broken any links?

[jcfr]

Thanks for the pull request 🙏

Considering that:

1. this pull request updates the archived extensions
2. existing extensions have already been updated through the pull requests referenced in Meta issue referencing extension updates #2041
3. re-build of Stable extensions to account for the updated extensions will be done tomorrow following the integration of bluestreak/overload: Move SlicerStable from "overload" to "bluestreak" DashboardScripts#70

... I am closing this pull request.

[Leengit]

Thank you for the clarification and for closing this pull request.

I don't see an easy way to check whether the list at #2041 includes a pull request that amends the Slicer/ExtensionsIndex/README.md link to https://www.slicer.org/slicerWiki/images/a/ab/Extensions-Index-to-Catalog-cycle.png. If that's not updated ....

[jcfr]

[...] a pull request that amends the Slicer/ExtensionsIndex/README.md

Thanks for the note, update of the README file has just been contributed into the following pull request:

• DOC: Update README to use "https" links #2061