fdo#80955 make calc_MS_Excel_97 filter default for xls ext.

Change-Id: I8fa095b45ea2fe1a07c1660d2efc24c73f7082da

filter/source/config/fragments/types/calc_MS_Excel_97.xcu

@@ -20,7 +20,7 @@
         <prop oor:name="URLPattern"/>
         <prop oor:name="Extensions"><value>xls xlc xlm xlw xlk</value></prop>
         <prop oor:name="MediaType"><value>application/vnd.ms-excel</value></prop>
-        <prop oor:name="Preferred"><value>false</value></prop>
+        <prop oor:name="Preferred"><value>true</value></prop>
         <prop oor:name="PreferredFilter"><value>MS Excel 97</value></prop>
         <prop oor:name="UIName">
             <value>Microsoft Excel 97/2000/XP/2003</value>