glance requires pyOpenSSL>=0.11

glance uses  OpenSSL.crypto.sign() and OpenSSL.crypto.verify(), which
are new in pyOpenSSL 0.11. Global requirements already fixed, do the
same change in glance

Change-Id: I20ba38a174548c5a5a501351fb9a1a33b235b0b4
Partial-Bug: #1268966
Merge "glance requires pyOpenSSL>=0.11" into stable/havana