Improving load balancer performance

Further improving load balancer performance by expiring
connections to servers with weights set to 0.

Signed-off-by: Andrew Kim <taeyeonkim90@gmail.com>

libnetwork/osl/namespace_linux.go

@@ -44,6 +44,9 @@ var (
 		// expires connection from the IPVS connection table when the backend is not available
 		// more info: https://github.com/torvalds/linux/blob/master/Documentation/networking/ipvs-sysctl.txt#L126:1
 		"net.ipv4.vs.expire_nodest_conn": {Value: "1", CheckFn: nil},
+		// expires persistent connections to destination servers with weights set to 0
+		// more info: https://github.com/torvalds/linux/blob/master/Documentation/networking/ipvs-sysctl.txt#L144:1
+		"net.ipv4.vs.expire_quiescent_template": {Value: "1", CheckFn: nil},
 	}
 )