Can not set values on immutable configuration mailjet.settings:APItoken

Problem/Motivation

When try to access the lists page, Getting this error
Drupal\Core\Config\ImmutableConfigException: Can not set values on immutable configuration mailjet.settings:APItoken. Use \Drupal\Core\Config\ConfigFactoryInterface::getEditable() to retrieve a mutable configuration object in Drupal\Core\Config\ImmutableConfig->set() (line 27 of /var/web/vd23262/app/releases/147/web/core/lib/Drupal/Core/Config/ImmutableConfig.php).

Steps to reproduce

Enable mailjet and mailjet_lists module and try to access
/admin/config/system/mailjet/mailjet-panel/list

Proposed resolution

Use \Drupal\Core\Config\ConfigFactoryInterface::getEditable() to retrieve a mutable configuration object