Update libkml link in Superbuild

WIP MR to trigger CI

Summary

Link to the libkml tar in SuperBuild is broken, this MR updates it.

Rationale

Explain the rationale for the changes (possible link to a Request For Comments or to an issue).

Implementation Details

libkml_1.3.0r864+dfsg.orig.tar.gz is used instead of the old libkml_1.3.0r863.orig.tar.gz

Copyright

The copyright owner is CNES and has signed the ORFEO ToolBox Contributor License Agreement.

Check before merging:

• All discussions are resolved
• At least 2 votes from core developers, no vote.
• The feature branch is (reasonably) up-to-date with the base branch
• Dashboard is green
• Copyright owner has signed the ORFEO ToolBox Contributor License Agreement
• Optionally, run git diff develop... -U0 --no-color | clang-format-diff.py -p1 -i on latest changes and commit