Pavel Balashov

### Context I observe the absence of contact header in 180 Ringing responses issued by Linphone. Here is the 180 Ringing response message sampled from linphone app installed on Debian...

**Describe the bug** Using code from example application https://www.pjsip.org/docs/book-latest/html/intro_pjsua2.html#using-in-python-application leads to segfault. **To Reproduce** Steps to reproduce the behavior: 1. Compile python bindings for debian 10, use latest swig for...