Use smaller value for exported images in HTML export filter.

By default it is 800px but as we normally use exported content in root ERP5 web sites smaller defaults is usually better (still it's an ugly hack).

cloudooo/handler/ooo/helper/unoconverter.py

@@ -99,6 +99,7 @@ class UnoConverter(object):
       property = PropertyValue('FilterData', 0,
                         uno.Any('[]com.sun.star.beans.PropertyValue',
                         (PropertyValue('IsExportNotes', 0, True, 0),
+                        PropertyValue('Width', 0, 640, 0),
                         PropertyValue('Format', 0, 2, 0),),), 0)
     elif filter_name == "impress_pdf_Export":
       property = PropertyValue('FilterData', 0,