Merge branch 'one_profil_per_default' into 'master'

By default, only one profile can be selected

Closes #191

See merge request !262

src/strass/strass_app/migrations/0003_auto_20201028_1803.py

@@ -35,7 +35,7 @@ def migration_code(apps, schema_editor):
     set_default_live_setting("show_email_as_message", "True")
     set_default_live_setting("min_num_referee", 0)
     set_default_live_setting("max_num_referee", 3)
-    set_default_live_setting("max_num_profile", 0)
+    set_default_live_setting("max_num_profile", 1)
     set_default_live_setting("visibility_of_global_grade", 'never')
     set_default_live_setting("show_key_date_after_call", True)
     set_default_live_setting("cv_enabled", True)