Remove redundant defaults and update http logic

frigate/events.py

@@ -79,6 +79,7 @@ class EventProcessor(threading.Thread):
                         area=event_data["area"],
                         has_clip=event_data["has_clip"],
                         has_snapshot=event_data["has_snapshot"],
+                        sub_label=None,
                     ).execute()
 
             elif event_type == "end":

frigate/http.py

@@ -163,9 +163,9 @@ def set_sub_label(id):
         )
 
     if request.json:
-        new_sub_label = request.json.get("subLabel", "")
+        new_sub_label = request.json.get("subLabel")
     else:
-        new_sub_label = ""
+        new_sub_label = None
 
 
     if new_sub_label:
@@ -188,7 +188,7 @@ def delete_sub_label(id):
             jsonify({"success": False, "message": "Event " + id + " not found"}), 404
         )
 
-    event.sub_label = ""
+    event.sub_label = None
     event.save()
     return make_response(
         jsonify({"success": True, "message": "Event " + id + " sub label removed"}), 200