Fix tests

Author: haacked

posthog/test/test_client.py

@@ -647,8 +647,8 @@ def test_basic_capture_with_feature_flags_returns_active_only(self, patch_flags)
                 timeout=3,
                 distinct_id="distinct_id",
                 groups={},
-                person_properties=None,
-                group_properties=None,
+                person_properties={},
+                group_properties={},
                 geoip_disable=True,
             )
 
@@ -711,8 +711,8 @@ def test_basic_capture_with_feature_flags_and_disable_geoip_returns_correctly(
                 timeout=12,
                 distinct_id="distinct_id",
                 groups={},
-                person_properties=None,
-                group_properties=None,
+                person_properties={},
+                group_properties={},
                 geoip_disable=False,
             )