USN-8847-2: OpenSSL vulnerabilities

USN-8847-1 fixed vulnerabilities in OpenSSL. This update provides the corresponding fix for OpenSSL on Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. Original advisory details: It was discovered that OpenSSL incorrectly handled certain certificate revocation list distribution point names.