Unassign assets from removed customer.

@@ -28,6 +28,7 @@ import org.thingsboard.server.common.data.id.CustomerId;
 import org.thingsboard.server.common.data.id.TenantId;
 import org.thingsboard.server.common.data.page.TextPageData;
 import org.thingsboard.server.common.data.page.TextPageLink;
+import org.thingsboard.server.dao.asset.AssetService;
 import org.thingsboard.server.dao.dashboard.DashboardService;
 import org.thingsboard.server.dao.device.DeviceService;
 import org.thingsboard.server.dao.entity.AbstractEntityService;
@@ -61,6 +62,9 @@ public class CustomerServiceImpl extends AbstractEntityService implements Custom
     private TenantDao tenantDao;
 
     @Autowired
+    private AssetService assetService;
+
+    @Autowired
     private DeviceService deviceService;
 
     @Autowired
@@ -96,6 +100,7 @@ public class CustomerServiceImpl extends AbstractEntityService implements Custom
             throw new IncorrectParameterException("Unable to delete non-existent customer.");
         }
         dashboardService.unassignCustomerDashboards(customer.getTenantId(), customerId);
+        assetService.unassignCustomerAssets(customer.getTenantId(), customerId);
         deviceService.unassignCustomerDevices(customer.getTenantId(), customerId);
         userService.deleteCustomerUsers(customer.getTenantId(), customerId);
         deleteEntityRelations(customerId);