Drop rtpldacpay and payload the LDAC encoded output manually in the RTP header.
The RTP payload seems to be required as it carries the frame count information. Right now, rtpldacpay does not add this so construct the RTP header and payload manually.
Strangely some devices like Shanling MP4 and Sony XM3 would still work without this while some like the Sony XM4 does not.
Fixes #1124 (closed).