HTTP/2: refuse streams with data until SETTINGS is acknowledged. A client is allowed to send requests before receiving and acknowledging the SETTINGS frame. Such a client having a wrong idea about the stream's could send the request body that nginx isn't ready to process. The previous behavior was to send RST_STREAM with FLOW_CONTROL_ERROR in such case, but it didn't allow retrying requests that have been rejected.

au BufRead,BufNewFile *.nginx set ft=nginx
au BufRead,BufNewFile */etc/nginx/* set ft=nginx
au BufRead,BufNewFile */usr/local/nginx/conf/* set ft=nginx
au BufRead,BufNewFile nginx.conf set ft=nginx