Default value of image field is not shown

The commit from #2336985: ctools_entity_field_content_type_render() unnecessarily alters field deltas creates the following problem. If a field is empty, it will not be shown even if there is a placeholder for this field which is not stored in the field table in the database. The real example is image field which can define the default image which must be shown if the field is empty. The patch solves this problem.