Excel export of content view containing a 'single vocabulary' widget with style class generates wrong output

Excel export generates HTML for single vocabulary widget if widget's attribute style class in Studio is set.

How to reproduce. In Studio:

• add a single vocabulary widget (i.e. metadata dc:nature, vocabulary nature) in the results tab of a content view (i.e. DefaultContentListingInNavigation)
• in the widget configuration, set attrinute Style class to myclass
• make sure that attribute Show CSV export of content view is checked
• deploy to a Nuxeo instance
• Navigate to a workspace/folder using the content view and click on icon Excel export

The generated CSV contains <span class="myclass"></span> in the cells rendering the dc:nature metadata.