Fix DS SSL keys not updating when updating CDN

[shamrickus]

What does this PR (Pull Request) do?

• This PR fixes Missing sync between Riak and Traffic-Ops on DS CDN change #1847

Which Traffic Control components are affected by this PR?

• Traffic Control Client (Go)
• Traffic Ops

What is the best way to verify this PR?

Given two CDNs x1 and x2:

• Create a DS y on CDN x1
• Generate SSL keys for y
• Update y to be on CDN x2
• Verify SSL keys are now on x2 and not x1

Run the api tests and verify that they pass. Note: the ssl keys test are marked as a system test as they need riak to work.

If this is a bug fix, what versions of Traffic Control are affected?

master (55b3b03)

The following criteria are ALL met by this PR

• This PR includes tests OR I have explained why tests are unnecessary
• This PR includes documentation OR I have explained why documentation is unnecessary
• This PR includes an update to CHANGELOG.md OR such an update is not necessary
• This PR includes any and all required license headers
• This PR ensures that database migration sequence is correct OR this PR does not include a database migration
• This PR DOES NOT FIX A SERIOUS SECURITY VULNERABILITY (see the Apache Software Foundation's security guidelines for details)

[mitchell852]

@shamrickus - is this related or a fix to #1847 ? If so, can you update the PR description and probably create a changelog entry noting that this was fixed.

[shamrickus]

Yes

[mitchell852]

@shamrickus - can you fix the conflict?

[shamrickus]

Done

[mitchell852]

Run the api tests and verify that they pass

Not sure you have to mention that anymore due to our nifty GHA that runs the API tests :)

[mitchell852]

LGTM. works as expected.