RFR: Use https:// everywhere

[Erik Helin]

Hi all,

please review this small patch that ensures what we use `https://` links in all our Markdown generated by the bots.

Thanks,
Erik

## Testing
- [x] `make test` on Linux x64

----------------

Commits:
 - 108c9e88: Use https:// everywhere

Changes: https://git.openjdk.java.net/skara/pull/277/files
 Webrev: https://webrevs.openjdk.java.net/skara/277/webrev.00
  Stats: 6 lines in 4 files changed: 0 ins; 0 del; 6 mod
  Patch: https://git.openjdk.java.net/skara/pull/277.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/277/head:pull/277

PR: https://git.openjdk.java.net/skara/pull/277