Set socket used for test to non-blocking.
Set socket used for test to non-blocking.

The socket being used to check if a controller is alive was blocking. It
blocked until it was able to connect to the given host and port.

Signed-off-by: Srijan Mishra <c2c41bdc8170583cc0b29d3ebd2deb0e30f77bb7@gmail.com>

routeflow/RouteFlow,srijanmishra/RouteFlow,arazmj/RouteFlow,c3m3gyanesh/RouteFlow-OpenConfig,c3m3gyanesh/RouteFlow-OpenConfig,srijanmishra/RouteFlow,arazmj/RouteFlow,raphaelvrosa/RouteFlow,routeflow/RouteFlow,c3m3gyanesh/RouteFlow-OpenConfig,ralph-mikera/RouteFlow-1,raphaelvrosa/RouteFlow,raphaelvrosa/RouteFlow,ralph-mikera/RouteFlow-1,srijanmishra/RouteFlow,arazmj/RouteFlow,ralph-mikera/RouteFlow-1,arazmj/RouteFlow,c3m3gyanesh/RouteFlow-OpenConfig,c3m3gyanesh/RouteFlow-OpenConfig,raphaelvrosa/RouteFlow,srijanmishra/RouteFlow,routeflow/RouteFlow,c3m3gyanesh/RouteFlow-OpenConfig,raphaelvrosa/RouteFlow,ralph-mikera/RouteFlow-1,ralph-mikera/RouteFlow-1,ralph-mikera/RouteFlow-1,routeflow/RouteFlow,arazmj/RouteFlow,arazmj/RouteFlow,srijanmishra/RouteFlow,raphaelvrosa/RouteFlow,routeflow/RouteFlow