Port Ruby 2.3.7 changes to EE
CE port of https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/18244
Tests in EE were failing because OpenSSL does not support AEAD in CBC mode. Only GCM ciphers have support for this (as confirmed by openssl ciphers -v
and in https://github.com/ruby/openssl/issues/49#issue-143818021). Ruby 2.3.7 appears to be enforcing this, while previous versions did not complain.
Edited by Stan Hu