Investigate the unexpected shutdown case

[burak-58]

Very rare unexpected shutdown case for v2.4.3 with this error:

Exception in thread "vert.x-eventloop-thread-45" java.lang.NullPointerException
at io.antmedia.enterprise.webrtc.codec.VirtualVideoEncoderFactory.getEnabledCodecList(VirtualVideoEncoderFactory.java:118)
at io.antmedia.enterprise.webrtc.codec.VirtualVideoEncoderFactory.getSupportedCodecs(VirtualVideoEncoderFactory.java:109)
at org.webrtc.PeerConnectionFactory.nativeCreatePeerConnectionFactory(Native Method)
at org.webrtc.PeerConnectionFactory$Builder.createPeerConnectionFactory(PeerConnectionFactory.java:258)
at io.antmedia.enterprise.adaptive.WebRTCEncoderAdaptor.createPeerConnectionFactory(WebRTCEncoderAdaptor.java:1148)
at io.antmedia.enterprise.adaptive.WebRTCEncoderAdaptor.initPeerConnection(WebRTCEncoderAdaptor.java:1264)
at io.antmedia.enterprise.adaptive.WebRTCEncoderAdaptor.lambda$setRemoteDescription$13(WebRTCEncoderAdaptor.java:1722)
at io.antmedia.enterprise.adaptive.WebRTCEncoderAdaptor.lambda$executeOnSignallingThread$19(WebRTCEncoderAdaptor.java:2221)
at io.vertx.core.impl.AbstractContext.dispatch(AbstractContext.java:100)
at io.vertx.core.impl.AbstractContext.dispatch(AbstractContext.java:63)
at io.vertx.core.impl.EventLoopContext.lambda$runOnContext$0(EventLoopContext.java:38)
at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:164)
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:469)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:500)
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:986)
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.base/java.lang.Thread.run(Thread.java:829)