Unable to publish content with default ez recommendation configuration.

Warning: in_array() expects parameter 2 to be array, null given

#1 vendor/ezsystems/recommendation-bundle/Client/YooChooseNotifier.php(134): in_array('article', NULL)
#2 vendor/ezsystems/recommendation-bundle/eZ/Publish/Slot/PublishVersion.php(21): 
EzSystems\RecommendationBundle\Client\YooChooseNotifier->updateContent(256)

Affects Version: >= 1.2

Solution: default value for `included_content_types` should be empty array, not null.