Internal links starting with http (not https) are not replaced while duplicating region contents

[MizukiTemma]

Describe the Bug

When you create a new region, you can import contents from an existing region (often from Deutschlandvorlage in the live system). If those contents contain region-internal links, the region slugs in the links will be replaced with that of the region being newly created.

Steps to Reproduce

1. Go to any region A and add into a page a link to a content of the region A with prefix http into a content.
2. Go to the network management and create a new region with importing contents from the region A
3. Go to the new region
4. See the region slug of the internal link is not replaced

If http://integreat.app/region_a/de/page_title/ is used in the step 1, http://integreat.app/new_region/de/page_title/ must appear in the step 4.
If https://integreat.app/region_a/de/page_title/ is used, https://integreat.app/new_region/de/page_title/ appears (success).

Expected Behavior

The region slug must be replaced even if URLs are starting with http instead of https

Actual Behavior

The region slug is not replaced.

Additional Information

Traceback

[david-venhoff]

Would this be solved if we implement #68?