Remove bogus config setting "AdminCanReadAll"

Authored by Legoktm on May 15 2018, 5:50 PM.

Description

Remove bogus config setting "AdminCanReadAll"

This isn't used by this extension, and appears to be accidentally
copied from AccessControl. While we're at it, remove the unused
"GraphVizRedirect" setting as well.

Bug: T194405
Change-Id: I7fc8c21ad5b3bdcf5abdff902dbe475186483594
(cherry picked from commit 4dd7815525a7ed6018cbedf93406d9d0a5cc7863)