Handle redirect on different base URL than source

[seifane]

We need to handle a redirect that isn't on the same domain as the source.

On way to do that would be to not strip the base url from the destination if it doesn't match the one from the source.

[superbiche]

@seifane we could do the following:

• if the value in the "source" column is an absolute URL, strip it but store the hostname as temp var. Otherwise skip
• if the value in "destination" column is also an absolute URL, and if it's different from the source hostname, keep the full URL
• if destination is the same hostname, keep only a relative path