Revert changes in 2.2.11 that caused an invalid

etag to be emitted for on-the-fly gzip content-encoding.
PR 39727 will require larger fixes and this fix was far more
harmful than the original code.

PR: 45023, 39727


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@761835 13f79535-47bb-0310-9956-ffa450edef68