Add SSL/TLS option to profile

This simple change adds in an option to set the use_ssl parameter in the profile by specifying smtp.tls.  The reason for the discrepancy is that the ec2-autoscale-reactor stack formula, at https://github.com/saltstack-formulas/ec2-autoscale-reactor, uses smtp.tls in the documentation.  TLS is the more generic term, so I stuck with that.