Fix accidental debug logging in the OCSP helper client

[sgmiller]

The OCSP client in sdk/ uses retryablehttp, whose clients bring their own
Logger to the party, with a default log level of DEBUG. This is in
opposition to the Loggers created in Vault. As such, OCSP requests get
logged even if the level is above DEBUG.

This PR configures the logger of the retryablehttp client to use the one
configured on the OCSP client itself.

Description

What does this PR do?

TODO only if you're a HashiCorp employee

• Backport Labels: If this PR is in the ENT repo and needs to be backported, backport
  to N, N-1, and N-2, using the backport/ent/x.x.x+ent labels. If this PR is in the CE repo, you should only backport to N, using the backport/x.x.x label, not the enterprise labels.
  • If this fixes a critical security vulnerability or severity 1 bug, it will also need to be backported to the current LTS versions of Vault. To ensure this, use all available enterprise labels.
• ENT Breakage: If this PR either 1) removes a public function OR 2) changes the signature
  of a public function, even if that change is in a CE file, double check that
  applying the patch for this PR to the ENT repo and running tests doesn't
  break any tests. Sometimes ENT only tests rely on public functions in CE
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CI Results:
All Go tests succeeded! ✅

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Build Results:
All builds succeeded! ✅

[stevendpclark]

👍