[maven-release-plugin] prepare for next development iteration
Set remoteVideo source to empty string on WebRtcPeer.dispose()

Change-Id: I11c062948db4b8649e1cec234facddf9e64d954e
Check if peerConnection was set previously to close it

Change-Id: I1649582d12c7a6be5dc12f8f501ef78a32d68b95
Package.json version updated to release version
[maven-release-plugin] prepare release kws-utils-4.3.21