rapid-cdn: refresh software.cfg.json md5 after serialisation override

Summary

Refresh stale md5 entry for software/rapid-cdn/software.cfg.json in software/rapid-cdn/buildout.hash.cfg.

Why

Commit 5b05605833 ("rapid-cdn: Serialize shared with XML") added two "serialisation": "xml" lines to software/rapid-cdn/software.cfg.json but did not refresh the md5 entry in buildout.hash.cfg.

The mismatch breaks every rapid-cdn SR build downstream:

2026-05-13 15:47:49 slapos[1552068] INFO Installing software.cfg.json.
2026-05-13 15:47:49 slapos[1552068] ERROR Error: MD5 checksum mismatch for local resource at
  '/srv/slapgrid/slappart2/.../parts/slapos-repository/software/rapid-cdn/software.cfg.json'.

This already broke CI on at least:

• !1975 — rapid-cdn-instancenode, latest run 20260513-B74DEB13 failed with setUpModule ERROR.

Reproduce

git checkout master
md5sum software/rapid-cdn/software.cfg.json
# a9e820401ed3afaf070ff24ceca6a434
grep -A2 '^\[software.cfg.json\]' software/rapid-cdn/buildout.hash.cfg
# md5sum = 4024c9884f45c3f1572cb40434effca5   ← stale

What changes

Single-line update in software/rapid-cdn/buildout.hash.cfg:169:

-md5sum = 4024c9884f45c3f1572cb40434effca5
+md5sum = a9e820401ed3afaf070ff24ceca6a434

Note to @luke

This MR is designed to be cherry-picked onto master quickly — it's a one-line hash refresh that fixes a regression introduced by your commit 5b05605833. Feel free to cherry-pick or absorb into a fixup; the branch will rebase clean.

Test plan

• CI green on this MR.
• Once merged, !1975 rapid-cdn integration test should no longer fail at setUpModule.

🤖 Generated with Claude Code