MFH: r508901

Security update nginx from 1.17.2 to 1.17.3.

Approved by: ports-secteam (implicitly).

<ChangeLog with nginx 1.17.3>

*) Security: when using HTTP/2 a client might cause excessive memory

consumption and CPU usage (CVE-2019-9511, CVE-2019-9513,
CVE-2019-9516).

*) Bugfix: "zero size buf" alerts might appear in logs when using

gzipping; the bug had appeared in 1.17.2.

*) Bugfix: a segmentation fault might occur in a worker process if the

"resolver" directive was used in SMTP proxy.

</ChangeLog>