Previously, `PagesDomain` would not allow a domain such as
123.example.com. With this change, this is now allowed, because
it is a perfectly valid domain.
aes-256-cbc is the default algorithm for attr_encrypted 1.x, but the default is changed in 3.0 and thus must be declared explicitly.
See https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4216/ for more information. This will prevent OpenSSL errors once the code from that MR is merged into EE.
