Catch HTTP error when trying to retrieve port bindings.
Catch HTTP error when trying to retrieve port bindings.

	- the client can throw a 404 not found error if the container is
	  already removed.  This is okay in most cases but there may be
	  an underlying issue.
	- 404 can happen in the following cases in which an error is
	  logged and continuation is fine:
	    - dc restart: The ssh tunnel isn't closed so no further action
	      is needed.
	    - dc stop: any missed tunnels will be closed on
	      docker-forward restart or stop.

vultron81/docker-forward