Applied patch #43

Closes #2741429

core/lib/Drupal/Core/Config/Entity/Exception/ConfigEntityDependencyException.php

+<?php
+
+namespace Drupal\Core\Config\Entity\Exception;
+
+use Drupal\Core\Config\ConfigException;
+
+/**
+ * Thrown when a configuration entity dependency does not exist.
+ */
+class ConfigEntityDependencyException extends ConfigException {}