Add [ssl] and 2 cinder attributes to nova.conf

This commit adds [ssl] section to nova.conf, which is used
to communicate with Glance when using https. It also adds
cinder_ca_certificates_file and cinder_api_insecure which are
needed for communicating with Cinder.

Change-Id: Id07f163dc7481ec26d0a5f8f1afb50e327318517
Closes-Bug: #1384118