BUG/MINOR: h2: don't send GOAWAY on failed response

BUG/MINOR: h2: don't send GOAWAY on failed response

As part of the detection for intentional closes, we can kill the
connection if a shutw() happens before the headers. But it can also
happen that an invalid response is not properly parsed, preventing
any headers frame from being sent and making the function believe
it was an abort. Now instead we check if any response was received
from the stream, regardless of the fact that it was properly
converted.