Assume this wants to append the numerical representation

...not a single sal_Unicode char (aParam.nUserIndex is of type sal_uInt16), just
the same as 2211ad69 "First cut on getting ODS
import/export of sheet-local anonymous ranges" did in a very similar place in
the same file.  (And Kohei, author of both places, assumes this is the right
thing to do, too.)

Change-Id: I12cd8abf1b4aaab7baa54f21d8c5a7ff2e171275

sc/source/filter/xml/XMLExportDatabaseRanges.cxx

@@ -354,7 +354,7 @@ private:
             {
                 OUStringBuffer aBuf;
                 aBuf.append(SC_USERLIST);
-                aBuf.append(aParam.nUserIndex);
+                aBuf.append(static_cast<sal_Int32>(aParam.nUserIndex));
                 mrExport.AddAttribute(XML_NAMESPACE_TABLE, XML_DATA_TYPE, aBuf.makeStringAndClear());
             }
             else