for libre: don't write in docx blank page border

word/Editor/Serialize2.js

@@ -1804,7 +1804,7 @@ function Binary_pPrWriter(memory, oNumIdMap, oBinaryHeaderFooterTableWriter, sav
 			this.bs.WriteItem(c_oSerProp_secPrType.pageNumType, function(){oThis.WritePageNumType(PageNumType);});
 		if(null != sectPr.Columns)
 			this.bs.WriteItem(c_oSerProp_secPrType.cols, function(){oThis.WriteColumns(sectPr.Columns);});
-		if(null != sectPr.Borders)
+		if(null != sectPr.Borders && !sectPr.Borders.IsEmptyBorders())
 			this.bs.WriteItem(c_oSerProp_secPrType.pgBorders, function(){oThis.WritePgBorders(sectPr.Borders);});
 		if(null != sectPr.FootnotePr)
 			this.bs.WriteItem(c_oSerProp_secPrType.footnotePr, function(){oThis.WriteFootnotePr(sectPr.FootnotePr);});