Ubuntu Security Notice USN-5487-3

Ubuntu Security Notice 5487-3 - USN-5487-1 fixed several vulnerabilities in Apache HTTP Server. Unfortunately it caused regressions. USN-5487-2 reverted the patches that caused the regression in Ubuntu 14.04 ESM for further investigation. This update re-adds the security fixes for Ubuntu 14.04 ESM and fixes two different regressions: one affecting mod_proxy only in Ubuntu 14.04 ESM and another in mod_sed affecting also Ubuntu 16.04 ESM and Ubuntu 18.04 LTS.