fixed 4614: infinite loop in Zend\Log\Formatter::normalize
Log formatter: Use JSON_UNESCAPE_[SLASHES|UNICODE] to generate better readable error messages
Merge branch 'hotfix/4615'

Close #4615
Fixes #4579
Merge pull request #4616 from marc-mabe/hotfix/4614

fixed 4614: infinite loop in Zend\Log\Formatter::normalize
Merge branch 'hotfix/4616' into develop

Forward port #4616