node-mysql2: The debug option stopped working in 1.6.2

It seems like version 1.6.2 broke the debug: true option from working. I was able to dissect it to the following change: https://github.com/sidorares/node-mysql2/commit/e0077c0892fa27fe4bd39334be4a29dfe1592d18

The commit adds 'use strict' to lib/connection.js but there is a debug log in there that uses arguments.callee which is an error under strict mode.

I’m not sure what the appropriate fix would be. A quick fix would be just to remove 'use strict', but not sure if there should be additional refactoring to just make it work under strict mode.