Restarting ocserv doesn't clean up all workers

[Niels Peen]

> It is printed on debug level. I've modified it now to print it on info
> level, but you should see something like:
> "main: termination request received; waiting for children to die"
> 
> Seeing it again there may be an issue in the way waitpid() is handled.
> That should fix it:
> http://git.infradead.org/ocserv.git/commitdiff/accdb24050a1de06c0408c9d783aa0575e35e831

The problem seems to starts earlier than that. When I let the server untouched for a while 
users started complaining that logins were rejected. The log indicates that ocserv believes 
these users are already connected a maximum number of times:

ocserv[21306]: main: 1.2.3.4:58843 user ‘XYZ' tried to connect more than 2 times

Doing a tcpdump on the interfaces created for this user showed no traffic at all, which is 
unlikely is something was truly connected.

Just to be sure I also did a tcpdump on the external interface to see if there was at least
some DPD traffic going to the client’s IP. There was none. 

Typical strace for these processes:

strace -p 21306
Process 21306 attached - interrupt to quit
recvfrom(8, 

These are also the processes that didn’t die after I restart ocserv.

Regards,
Niels