💚 Fix linters

apps/activity/admin.py

@@ -2,8 +2,8 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 
 from django.contrib import admin
-
 from note_kfet.admin import admin_site
+
 from .models import Activity, ActivityType, Guest, Entry
 
 

apps/activity/models.py

@@ -1,11 +1,11 @@
 # Copyright (C) 2018-2020 by BDE ENS Paris-Saclay
 # SPDX-License-Identifier: GPL-3.0-or-later
+
 from datetime import timedelta, datetime
 from threading import Thread
 
 from django.conf import settings
 from django.contrib.auth.models import User
-from django.core.management import call_command
 from django.db import models
 from django.db.models import Q
 from django.utils import timezone