Don't wait to consume the entire request body for Connection: close requests

[halter73]

If you hit a sample app running on Kestrel with ab (apache bench which makes HTTP/1.0 requests), every request times out.

This is caused by Kestrel becoming stuck on await messageBody.Consume() in Frame.RequestProcessingAsync.

I think we fix this by simply not consuming the rest of the request for non keep-alive connections.

[benaadams]

Was putting a PR together for this but it needs to go after "Precomputed header bytes" #367 if that's happening as its all change

[cesarblum]

@benaadams The fix is simple. I was thinking something like:

if (_keepAlive)
{
    // Finish reading the request body in case the app did not.
    await messageBody.Consume();
}

Is this what you were thinking? The only reason this isn't in a PR yet is we need a regression test.

[benaadams]

@CesarBS yes, good point :)

[cesarblum]

Closed by e4fd91b.

[amcdnl]

@CesarBS Is this related? BrowserSync/browser-sync#905

[cesarblum]

@amcdnl Looks like it.