update behaviour of migrate_to_different_site in IP Trunk migration

gso/workflows/iptrunk/migrate_iptrunk.py

@@ -85,8 +85,8 @@ def initial_input_form_generator(subscription_id: UUIDstr) -> FormGenerator:
             current_router_site = Router.from_subscription(router_id).router.router_site.subscription
             old_side_site = Router.from_subscription(migrate_form_input.replace_side).router.router_site
             if (
-                migrate_form_input.migrate_to_different_site
-                and current_router_site.subscription_id == old_side_site.owner_subscription_id
+                not migrate_form_input.migrate_to_different_site
+                and current_router_site.subscription_id != old_side_site.owner_subscription_id
             ):
                 continue
             routers[str(router_id)] = router["description"]

test/workflows/iptrunk/test_migrate_iptrunk.py

@@ -76,6 +76,7 @@ def migrate_form_input(
         {
             "tt_number": faker.tt_number(),
             "replace_side": replace_side,
+            "migrate_to_different_site": True,
         },
         {
             "new_node": new_router,