fixed an issue with ipv4 whitelist being intialized for ipv6.

[dneuman64]

What does this PR (Pull Request) do?

• This PR fixes Anonymous blocking - ip4Whitelist does not work #3661

Which Traffic Control components are affected by this PR?

• Traffic Router

What is the best way to verify this PR?

Setup Anonymous Proxy blocking for a DS
Verify an IP is blocked
Add the IP to the whitelist
Re-test and verify the IP is allowed

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

All versions

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)

Additional Information

[mitchell852]

@dneuman64 - can you add a changelog.md entry under the unreleased / Fixed section?

[dneuman64]

hmm, I thought I did. Maybe I didn't commit

[dneuman64]

There we go, forgot to push. Done @mitchell852

[rawlinp]

LGTM