Change nested list style to use letters

Author: selfissued

openid-federation-1_0.xml

@@ -3580,7 +3580,7 @@
               </t>
             </list>
               Furthermore, the following requirements MUST be met:
-              <list>
+              <list style="letters">
                   <t>
                       If the delegation JWT has an <spanx style="verb">exp</spanx> claim,
                       the expiration time MUST NOT have been reached.