Fatal error: should not happen

[weissi]

async-http-client/Sources/AsyncHTTPClient/ConnectionsState.swift

Line 232 in 238c653

assertionFailure("should not happen")

this assertion can easily be hit by putting the following code into the HTTPBinHandler:

    func errorCaught(context: ChannelHandlerContext, error: Error) {
        context.close(promise: nil)
    }

and then running the tests. I believe this is a real error that is likely to happen.

[artemredkin]

This is a duplicate of #248