While I suspect not too many people will find this useful, I wanted to share this as I ran into a series of events that requires me to use xf 1.5 for a while longer, and our MySQL connections are required to go over SSL.
It should be possible to modify the library/Zend/Db/Adaptor/Mysqli.php file to include the SSL support that is required. This is based on connecting to an Managed Azure MySQL server, but would imagine it should work for Linode, or other managed servers.
MySQLi supports database connections over SSL but XenForo doesn't (from what I can tell). Adding support for this should be simple. Just add a few config.php options then make the necessary changes to \XF\Db\Mysqli\Adapter::makeConnection from what I can gather. Any reason why this isn't...