don't call ngx_http_finalize_request() on URI parsing error
don't call ngx_http_finalize_request() on URI parsing error

This replaces the ngx_http_process_request_uri() call, which calls
ngx_http_finalize_request() on error, to avoid sending an HTTP
error response when we haven't sent a PUSH_PROMISE yet.

The other fields (host, headers) get copied from the original request so
they have already been validated, and parsing them won't fail, so we don't
need to do the same in those cases.

ghedo/http2-push-nginx-module