[change] Changed the delete_old_radiusbatch_users command to use days…

… instead of months openwisp#525

Changed the delete_old_radiusbatch_users command to take in days in argument instead of months and modified tests and tasks accordingly.

Fixes openwisp#525

openwisp_radius/settings.py

@@ -45,7 +45,7 @@ def get_default_password_reset_url(urls):
 DEFAULT_SECRET_FORMAT = get_settings_value('DEFAULT_SECRET_FORMAT', 'NT-Password')
 DISABLED_SECRET_FORMATS = get_settings_value('DISABLED_SECRET_FORMATS', [])
 BATCH_DEFAULT_PASSWORD_LENGTH = get_settings_value('BATCH_DEFAULT_PASSWORD_LENGTH', 8)
-BATCH_DELETE_EXPIRED = get_settings_value('BATCH_DELETE_EXPIRED',30 * 18)
+BATCH_DELETE_EXPIRED = get_settings_value('BATCH_DELETE_EXPIRED', 30 * 18)
 BATCH_MAIL_SUBJECT = get_settings_value('BATCH_MAIL_SUBJECT', 'Credentials')
 BATCH_MAIL_SENDER = get_settings_value('BATCH_MAIL_SENDER', settings.DEFAULT_FROM_EMAIL)
 API_AUTHORIZE_REJECT = get_settings_value('API_AUTHORIZE_REJECT', False)