Honor stream->weight even if stream->last_writelen is 0
Honor stream->weight even if stream->last_writelen is 0

wzyboy/nghttp2,serioussam/nghttp2,lukw00/nghttp2,thinred/nghttp2,thinred/nghttp2,wzyboy/nghttp2,serioussam/nghttp2,wzyboy/nghttp2,thinred/nghttp2,thinred/nghttp2,icing/nghttp2,icing/nghttp2,wzyboy/nghttp2,wzyboy/nghttp2,icing/nghttp2,thinred/nghttp2,serioussam/nghttp2,thinred/nghttp2,serioussam/nghttp2,icing/nghttp2,lukw00/nghttp2,wzyboy/nghttp2,lukw00/nghttp2,lukw00/nghttp2,wzyboy/nghttp2,lukw00/nghttp2,serioussam/nghttp2,icing/nghttp2,serioussam/nghttp2,icing/nghttp2,lukw00/nghttp2,serioussam/nghttp2,lukw00/nghttp2,icing/nghttp2,thinred/nghttp2