Disable Jenkins' CompressionFilter.

https://issues.jenkins-ci.org/browse/JENKINS-14362 indicates that
disabling Jenkins' compression filter corrects problems with zip
deflation threads in Jenkins that use up all available CPU time. Disable
the CompressionFilter in an attempt to work around this problem.

Change-Id: I5179fe54e6c942880bc75ef35e0b71ceb8773b30
Reviewed-on: https://review.openstack.org/25848
Reviewed-by: James E. Blair <corvus@inaugust.com>
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Approved: Jeremy Stanley <fungi@yuggoth.org>
Tested-by: Jenkins