Add fix for vapp.RemoveNetwork() and vapp.RemoveNetworkAsync() (#299)

* Use HTTP DELETE call instead of vApp network update to remove vApp networks

CHANGELOG.md

@@ -11,6 +11,8 @@ NOTES:
 BUGS FIXED:
 * Fix issue in Queries with vCD 10 version, which do not return network pool or provider VDC[#293](https://github.com/vmware/go-vcloud-director/pull/293)
 * Session timeout for media, catalog item upload  [#294](https://github.com/vmware/go-vcloud-director/pull/294)
+* Fix `vapp.RemoveNetwork`, `vapp.RemoveNetworkAsync` to use `DELETE` API call instead of update
+  which can apply incorrect remaining vApp network configurations [#299](https://github.com/vmware/go-vcloud-director/pull/299)
 
 ## 2.6.0 (March 13, 2010)
 

govcd/vapp.go

@@ -1194,24 +1194,25 @@ func (vapp *VApp) RemoveNetworkAsync(identifier string) (Task, error) {
 	}
 
 	networkConfigurations := vapp.VApp.NetworkConfigSection.NetworkConfig
-	isNetworkFound := false
-	for index, networkConfig := range networkConfigurations {
+	for _, networkConfig := range networkConfigurations {
 		networkId, err := GetUuidFromHref(networkConfig.Link.HREF, false)
 		if err != nil {
 			return Task{}, fmt.Errorf("unable to get network ID from HREF: %s", err)
 		}
 		if networkId == identifier || networkConfig.NetworkName == identifier {
-			isNetworkFound = true
-			networkConfigurations = append(networkConfigurations[:index], networkConfigurations[index+1:]...)
-			break
+			deleteUrl := vapp.client.VCDHREF.String() + "/network/" + networkId
+			errMessage := fmt.Sprintf("detaching vApp network %s (id '%s'): %%s", networkConfig.NetworkName, networkId)
+			task, err := vapp.client.ExecuteTaskRequest(deleteUrl, http.MethodDelete, types.AnyXMLMime, errMessage, nil)
+			if err != nil {
+				return Task{}, err
+			}
+
+			return task, nil
 		}
 	}
 
-	if !isNetworkFound {
-		return Task{}, fmt.Errorf("network to remove %s, wasn't found", identifier)
-	}
+	return Task{}, fmt.Errorf("network to remove %s, wasn't found", identifier)
 
-	return updateNetworkConfigurations(vapp, networkConfigurations)
 }
 
 // Removes vApp isolated network