Make the 400 error handler better (#365)

This error handler does nothing but hide the real problem. Make
it more like the others.

Still, I'm not sure why any of these exist. All they really seem
to do is obfuscate the real problem. OK, I guess they add app
logging, but even the ones that pass through 'error' are probably
hiding a lot of other useful information?

Signed-off-by: Adam Williamson <awilliam@redhat.com>

Author: AdamWill

resultsdb/__init__.py

@@ -198,7 +198,8 @@ def register_handlers(app):
     # TODO: find out why error handler works for 404 but not for 400
     @app.errorhandler(400)
     def bad_request(error):
-        return jsonify({"message": "Bad request"}), 400
+        app.logger.error("Bad request: %s", error)
+        return jsonify({"message": str(error)}), 400
 
     @app.errorhandler(401)
     def unauthorized(error):