Fixes a bug where if a stream monitor thread was not created (caused from failure of opening or starting the stream) pthread_cancel was called with an invalid thread ID.

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@114888 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_console.c

@@ -393,7 +393,7 @@ return_unlock:
 
 static int stop_stream(struct console_pvt *pvt)
 {
-	if (!pvt->streamstate)
+	if (!pvt->streamstate || pvt->thread == AST_PTHREADT_NULL)
 		return 0;
 
 	pthread_cancel(pvt->thread);