Image without specified document reference are unnecessary modified when published

Related code : https://github.com/xwiki-contrib/workflow-publication/blob/a56356f4ae0344f71c00c36ca2a9d5981ffd7461/xwiki-workflow-publication-api/src/main/java/org/xwiki/workflowpublication/internal/ReferencesTransformDocPublishingEventListener.java#L180
 
imageBlock.isFreeStandingURI results with the following cases :

• image:myImage.ext -> true
• [[image:myImage.ext]] -> false
   
  This second case must be taken in account in order to not apply reference modification on it.