RFR: cli: use credentials when pushing to https URLs

[Erik Helin]

Hi all,

please review this patch that makes `git-sync` and `git-publish` use credentials
when they are pushing to `https://` URLs. I also update all `git-pr` to approve
credentials that have been used successfully.

Testing:
- Manual testing of `git-sync`, `git-publish` and `git-pr` together with
  `https://` URLs

Thanks,
Erik

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Commit messages:
 - cli: use credentials when pushing to https URLs

Changes: https://git.openjdk.java.net/skara/pull/541/files
 Webrev: https://webrevs.openjdk.java.net/skara/541/webrev.00
  Stats: 76 lines in 3 files changed: 72 ins; 4 del; 0 mod
  Patch: https://git.openjdk.java.net/skara/pull/541.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/541/head:pull/541

PR: https://git.openjdk.java.net/skara/pull/541