Delete happening twice on change with ForceNew

[svend]

When I change a resource setting that uses ForceNew, delete happens twice. For example, when I change the name for the foo stingray_traffic_ip_group resource the resource is deleted, then another delete fails because the resource no longer exists.

$ terraform plan
-/+ stingray_traffic_ip_group.foo
name: "foo" => "foo-new" (forces new resource)

$ terraform apply
stingray_traffic_ip_group.foo: Refreshing state... (ID: foo)
stingray_traffic_ip_group.foo: Destroying...
stingray_traffic_ip_group.foo: Destruction complete
stingray_traffic_ip_group.foo: Modifying...
name: "foo" => "foo-new"
stingray_traffic_ip_group.foo: Error: DELETE https://localhost:9070/api/tm/3.0/config/active/traffic_ip_groups/foo: 404 resource.not_found Resource '/api/tm/3.0/config/active/traffic_ip_groups/foo' does not exist

The provider source is not on GitHub yet, but the resource code is here:

https://gist.github.com/svend/9299368667e086430c1b

[armon]

Should be fixed by #578