Return complete message error on payload / choose timeout (now fixed at 20 sec.)

[hammeronthenet]

Hi,
I think it could be good things:

• In case of status 400, get the complete error message in msg.payload (and not only a "static" message as now)

• Give to the user the possibility to change timeout ( I see now it's fixed at 20000 ms = 20 sec)

Thank you!

[rgstephens]

Good idea. If you'd like to work on that, please submit a PR.