Fix: assign correct subnet CIDR as a DHCP router option

Change-Id: Ib79b4d5f2396f0295f28ede7db00cf68c84e2a51
diff --git a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackSwitchingDhcpHandler.java b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackSwitchingDhcpHandler.java
index a769759..65afbf8 100644
--- a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackSwitchingDhcpHandler.java
+++ b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackSwitchingDhcpHandler.java
@@ -401,7 +401,7 @@
             option = new DhcpOption();
             option.setCode(OptionCode_RouterAddress.getValue());
             option.setLength((byte) 4);
-            option.setData(gatewayIp.toOctets());
+            option.setData(Ip4Address.valueOf(osSubnet.getGateway()).toOctets());
             options.add(option);
 
             // end option