Handle reinv_brkn1 test case from #voiptests gracefully:
Handle reinv_brkn1 test case from #voiptests gracefully:

 o Send 502 Bad Gateway to the UAC with the explanation set in the
   Warning header;

 o Disconnect the call, since now it's in the mixed state.

sippy/rtpproxy,sippy/rtpproxy,sippy/rtp_cluster,synety-jdebp/rtpproxy,jevonearth/rtpproxy,dsanders11/rtpproxy,dsanders11/rtpproxy,synety-jdebp/rtpproxy,synety-jdebp/rtpproxy,jevonearth/rtpproxy,synety-jdebp/rtpproxy,jevonearth/rtpproxy,jevonearth/rtpproxy,sippy/rtp_cluster,sippy/rtpproxy,dsanders11/rtpproxy