Changes

Summary

sip.c: permit early media with both 183 and 180 (details)

Commit 50c56845614aa9a528f106a42d0beb8e62e10bdd by laforge

sip.c: permit early media with both 183 and 180

So far we only attempted to extract SDP (and hence enable early media)
when receiving a status code 183.  However, SDP can also be provided
with 180, see for example https://developer.signalwire.com/freeswitch/FreeSWITCH-Explained/Codecs-and-Media/Early-Media/vs-183-vs-Early-Media_7143480/

Change-Id: Ia0072080c2e0bfb8b2bf751a248d3410a7723e79
Closes: OS#6559

src/sip.c