[0.15.0] `linux-x86_64` JAR missing

[boris-petrov]

Congrats on the new release! A bunch of the platform-specific JARs are missing though:

https://repo.maven.apache.org/maven2/dev/onvoid/webrtc/webrtc-java/0.15.0/
vs
https://repo.maven.apache.org/maven2/dev/onvoid/webrtc/webrtc-java/0.14.0/