allow session name to be missing

[nemosupremo]

Like #13, I've come across a camera (anycon) that doesn't provide a session name:

v=0\r
o=- 1721088675 1721088675 IN IP4 192.168.3.27\r
c=IN IP4 192.168.3.27\r
t=0 0\r
m=video 0 RTP/AVP 96\r
c=IN IP4 0.0.0.0\r
b=AS:5000\r
a=control:trackID=0\r
a=rtpmap:96 H265/90000\r
a=x-dimensions:2592,1944\r
a=framerate:30\r
a=bitrate:4096\r
a=fmtp:96 profile-space=0;profile-id=1;tier-flag=0;level-id=150;nterop-constraints=000000000000;sprop-vps=QAEMAf//AWAAAAMAAAMAAAMAAAMAlqwJ;sprop-sps=QgEBAWAAAAMAAAMAAAMAAAMAlqABRCAHmWNrkkya5ZwCAAAH0gAA6pwQ;sprop-pps=RAHgdrAmQA==\r
m=audio 0 RTP/AVP 8\r
a=control:trackID=1\r
a=rtpmap:8 PCMA/8000\r
a=x-onvif-track:audiotrack_token\r
b=AS:50\r
a=recvonly\r

Like the fix for #13, this simply makes the session name an empty string when it is not present.

[sdroege]

Thanks, looks good to me but can you change it so that cargo clippy still passes?

[sdroege]

I can't push a rebased version to your branch due to missing permissions, so I'm going to merge it manually.

[sdroege]

That's merged in 723e08b