style: add missing blank lines before TestResolveProperties class

Author: tobixen

tests/test_caldav_unit.py

@@ -2809,6 +2809,8 @@ def test_get_method_retries(self, mocked):
         response = client.request("/", "GET")
         assert response.status == 207
         assert mocked.call_count == 2
+
+
 class TestResolveProperties:
     """Tests for _resolve_properties unbound variable bug (issue #647 / calendar-cli #114)."""