If our connection is explicitly non-strict, tell MySQL

We default to making the connection strict, but have historically relied on the MySQL default when we want it to be non-strict. On some (recent?) versions of MySQL, new connections default to being strict, so if we've been told 'strict:false', we're obliged to pass that on.

This fixes a test failure that we've seen turn up on relatively-new development machines, so we do already have a test covering it.

Specifically, a bunch of the OpenAcademy students were seeing this, and we just told them to ignore it at the time. :neutral_face: 

... and I was also seeing it, but I rarely run MySQL tests locally. :neutral_face:  :neutral_face: