### Description
On systems running libssl 1.1+, the compile flag `TLS_PTHREAD_MUTEX_SHARED` is
set to avoid an issue with deadlocks. However, if the system does not have
`pkg-config` installed, the build completes successfully without setting this
compile flag. As such, users with this
@rfuchs Thank you for this. I can confirm that this fixes the issue.
```
Feb 14 20:33:51 debian-kamailio kamailio[5066]: INFO: {1 63658613 INVITE
98dbb579-2773-123c-48af-80fa5d718101}
In this test it was 1 rtpengine daemon. The delete method was tried 30 times to
the same IP:port, each try was 5 inner retries, so 150 times in total.
You get the same effect with more rtpengine daemons where a call is attempting
to complete using a failed daemon.
In the logs, 192.168.X.X
## Description
When one rtpengine instance becomes unavailable on a Kamailio instance with
moderate call traffic, even where there are multiple rtpengine instances
configured for high availability, all processes can become blocked and Kamailio
stops responding to all requests.
We produced
