fix: cannot call close if body is null

[shawkins]

Description

Follow-up to a potential okhttp issue - while we don't have a reproducer it's clear we are checking if the body can be null further down in the method so it should be done at the top instead of just calling response close (which is documented as just a body close).

close: #7087

Type of change

• Bug fix (non-breaking change which fixes an issue)
• Feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change
• Chore (non-breaking change which doesn't affect codebase;
  test, version modification, documentation, etc.)

Checklist

• Code contributed by me aligns with current project license: Apache 2.0
• I Added CHANGELOG entry regarding this change
• I have implemented unit tests to cover my changes
• I have added/updated the javadocs and other documentation accordingly
• No new bugs, code smells, etc. in SonarCloud report
• I tested my code in Kubernetes
• I tested my code in OpenShift

[manusa]

LGTM, thx!