CVE-2016-9015: Correct set verify flags.
CVE-2016-9015: Correct set verify flags.

This error, introduced in 1.17, causes users using OpenSSL 1.1.0 along
with PyOpenSSL to silently fail to validate certificates. This is an
alarming failure mode, and is currently being worked on as part of
OpenSSL 1.1.0: https://github.com/openssl/openssl/pull/1793

Lukasa/urllib3,urllib3/urllib3,Disassem/urllib3,sigmavirus24/urllib3,Lukasa/urllib3,urllib3/urllib3,sigmavirus24/urllib3,Disassem/urllib3