[UBUNTU] USN-6841-2: PHP vulnerability

[1s2k.pl]

USN-6841-1 fixed a vulnerability in PHP. This update provides the corresponding updates for Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. Original advisory details: It was discovered that PHP could early return in the filter_var function resulting in invalid user information being treated as valid user information. An attacker could possibly use this issue to expose raw user input information.