Avoid CivetWeb crash if no optional port could be bound

[DL6ER]

What does this implement/fix?

Do not try to start API if no ports succeeded binding. This circumvents a bug resulting in a crash in CivetWeb. See upstream issue report at civetweb/civetweb#1327

Should be merged after #2312 as it is based on it to know when we bound to ports (and when not).

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Related issue or feature (if applicable): Fixes #2250

Pull request in docs with documentation (if applicable): N/A

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5. I have squashed any insignificant commits. (git rebase)

Checklist:

• The code change is tested and works locally.
• I based my code and PRs against the repositories developmental branch.
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[DL6ER]

Submitted upstream as civetweb/civetweb#1328. This PR is equivalent and should be merged to our codebase when the bugfix is accepted as-is upstream.

[DL6ER]

Confirmed by OP in #2250 (comment)

[PromoFaux]

Approving based on OPs confirmation

The merge-base changed after approval.

[DL6ER]

Rebased on latest development as the review was anyway "gone" after I had merged other PRs. The dismissal seems to have happened automatically because the PR where this was based on was merged before.