DOCX export: declare wpg namespace

Change-Id: If204d95142826d4cc194aed8a97c68a121187b8a

oox/source/token/tokens.txt

@@ -5663,6 +5663,7 @@ wrapTopAndBottom
 wrapTrailSpaces
 wrapcoords
 writeProtection
+wpg
 wps
 wsp
 wsDr

sw/source/filter/ww8/docxexport.cxx

@@ -1058,6 +1058,7 @@ XFastAttributeListRef DocxExport::MainXmlNamespaces( FSHelperPtr serializer )
     pAttr->add( FSNS( XML_xmlns, XML_w10 ), "urn:schemas-microsoft-com:office:word" );
     pAttr->add( FSNS( XML_xmlns, XML_wp ), "http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawing" );
     pAttr->add( FSNS( XML_xmlns, XML_wps ), "http://schemas.microsoft.com/office/word/2010/wordprocessingShape" );
+    pAttr->add( FSNS( XML_xmlns, XML_wpg ), "http://schemas.microsoft.com/office/word/2010/wordprocessingGroup" );
     pAttr->add( FSNS( XML_xmlns, XML_mc ), "http://schemas.openxmlformats.org/markup-compatibility/2006" );
     return XFastAttributeListRef( pAttr );
 }