Add print statement if smoke fails to start so user knows what cause was

Took me a few minutes to figure out smoke wasn't able to bind to a port because it was in use so I thought this would be a helpful change.

It will print a message like this:
	ERROR - not listening on port 7771 due to exception: org.jboss.netty.channel.ChannelException: Failed to bind to: 0.0.0.0/0.0.0.0:7771