When `writeHear` of `Http2ServerResponse` instance are called with 204,
205 and 304 status codes an underlying stream closes.
If call `end` method after sending any of these status codes it will
cause an error `TypeError: Cannot read property 'Symbol(trailers)' of
undefined` because a reference to `Http2ServerResponse` instance
associated with Http2Stream already was deleted.
The closing of stream causes emitting `watiTrailers` event and, when
this event handles inside `onStreamTrailerReady`  handler, there is
no reference to Http2ServerResponse instance.

Fises: #21740

…nd_after_writeHead