Do not remove RestDevices when shutting down the RestDeviceProvider

Change-Id: I080761af800ae60b3fe2d80d73425872c15f33fa
diff --git a/providers/rest/device/src/main/java/org/onosproject/provider/rest/device/impl/RestDeviceProvider.java b/providers/rest/device/src/main/java/org/onosproject/provider/rest/device/impl/RestDeviceProvider.java
index 3e97a3d..5e33c1d 100644
--- a/providers/rest/device/src/main/java/org/onosproject/provider/rest/device/impl/RestDeviceProvider.java
+++ b/providers/rest/device/src/main/java/org/onosproject/provider/rest/device/impl/RestDeviceProvider.java
@@ -164,7 +164,6 @@
     @Deactivate
     public void deactivate() {
         cfgService.removeListener(configListener);
-        controller.getDevices().keySet().forEach(this::deviceRemoved);
         providerRegistry.unregister(this);
         providerService = null;
         factories.forEach(cfgService::unregisterConfigFactory);