Update to 2.9.16.1

re: https://blog.snort.org/2020/08/snort-29161-has-been-released.html

• Added support for GCC version 10.1.1
• Added packet counters to make sure flows with one-way data don't pend forever.
• Fixed potential race condition between reload and exit path.

Notes for versions this port has skipped over:

re: https://blog.snort.org/2020/04/snort-29160-has-been-released.html