further changes, migrate to mysql2

lib/routes/api/error.js

@@ -9,7 +9,7 @@ function sysError(logger, res, err) {
     logger.info(err, 'unprocessable request');
     return res.status(422).json({msg: err.message});
   }
-  if (err.message.includes('ER_DUP_ENTRY')) {
+  if (err.code === 'ER_DUP_ENTRY') {
     logger.info(err, 'duplicate entry on insert');
     return res.status(422).json({msg: err.message});
   }