Fixes the following security issues:
Security: when using HTTP/2 a client might cause excessive memory
consumption and CPU usage (CVE-2019-9511, CVE-2019-9513,
CVE-2019-9516).
For details, see the advisory:
https://mailman.nginx.org/pipermail/nginx-announce/2019/000249.html
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit 24309ef4ab)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>