NiceHash connection problem... "error":null in json responses

[vkynchev]

When trying to connect NiceHash to Coiniumserv it doesn't - there was a problem with the JsonRpc library not sending "error": null. Fixed it and commited it to my repo... @vagabondan If you want you could merge it with this repo.

[vagabondan]

I've merged it with your previous pull request

[vkynchev]

Ok... Sorry for the issue...

[vagabondan]

@vkynchev Let's here try to invent constant solution for JsonRpc library. I agree with you that we can't change behaviour of the wrapper library directly, but using our own build of nuget library should be considered rather temporary workaround than constant solution.

[vagabondan]

Added library to repository as temporary workaround, but we still need to come up with something as constant solution.