* mod/mod_authz_host.xml:

note negation of env-var (env=!)

* howto/access.xml
add an example of env=! (revert r665707)

PR: 44901

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@675570 13f79535-47bb-0310-9956-ffa450edef68