pytest_suite: fix hardcoded absolute paths in .htaccess files

pytest_suite: fix hardcoded absolute paths in .htaccess files

Both files were committed with /Users/jjagielski/... paths that only
work on one developer's machine.

autoindex2/dir_protected/.htaccess: AuthUserFile now uses a path
relative to ServerRoot (Apache 2.4+ resolves these against the
configured ServerRoot, which the test framework sets to pytest_suite/t/).

setenvif/htaccess/.htaccess: file() argument in SetEnvIfExpr now uses
%{DOCUMENT_ROOT} instead of a hardcoded absolute path.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1934937 13f79535-47bb-0310-9956-ffa450edef68