Add Apache HTTPD Configuration for Kerberos with pgAdmin

Checklist:

[x] Have you added an explanation of what your changes do and why you'd like them to be included?
[ ] Have you updated or added documentation for the change, as applicable?
[x] Have you tested your changes on all related environments with successful results, as applicable?

Type of Changes:

[ ] Bug fix (non-breaking change which fixes an issue)
[x] New feature (non-breaking change which adds functionality)
[ ] Breaking change (fix or feature that would cause existing functionality to change)

What is the new behavior (if this is a feature change)?

Adds needed configuration settings for pgAdmin integration with Kerberos.

Other information:

CrunchyData / crunchy-containers