Backwards compatibility in remove method.

Checking if NSG was not set which means it was created prior to new version. This will then just check for the default named one.

Signed-off-by: Mitchell Maler <mitchell.maler@live.com>

drivers/azure/azure.go

@@ -434,6 +434,11 @@ func (d *Driver) Remove() error {
 	if err := c.DeletePublicIPAddressIfExists(d.ResourceGroup, d.naming().IP()); err != nil {
 		return err
 	}
+	// Check if network security group was set by optional param and if not set it from naming.
+	// included for backwards compatibility else nsgs prior without name will be orphaned.
+	if d.NetworkSecurityGroup == "" {
+		d.NetworkSecurityGroup = d.naming().NSG()
+	}
 	if err := c.CleanupNetworkSecurityGroupIfExists(d.ResourceGroup, d.NetworkSecurityGroup); err != nil {
 		return err
 	}