Fix or remove a few unhelpful debug logs

[rawlinp]

What does this PR do?

Fixes or removes a few unhelpful debug logs that I've found.

Which TC components are affected by this PR?

• Documentation
• Grove
• Traffic Analytics
• Traffic Monitor
• Traffic Ops
• Traffic Ops ORT
• Traffic Portal
• Traffic Router
• Traffic Stats
• Traffic Vault
• Other _________

What is the best way to verify this PR?

cd trafficcontrol/traffic_ops/traffic_ops_golang
go test -v origin/*
go test -v server/*

Start up traffic_ops_golang with debug logging enabled and send it any request, grep the output for DEBUG plugins.OnRequest calling.

Check all that apply

• This PR includes tests
• This PR includes documentation updates
• This PR includes an update to CHANGELOG.md
• This PR includes all required license headers
• This PR includes a database migration (ensure that migration sequence is correct)
• This PR fixes a serious security flaw. Read more: www.apache.org/security

[asfgit]

Refer to this link for build results (access rights to CI server needed):
https://builds.apache.org/job/trafficcontrol-PR/2641/
Test PASSed.