Change query to setnick for setting Nick

xep-0369.xml

@@ -45,6 +45,7 @@
       Remove namespace references in Info/Config nodes;
       Modify Participant and JID Map syntaxes;
       Clarifications on subscription to participants node and using this to receive Nick changes;
+      Replace use of "query" as MIX defined operations for setting nick; 
     </p></remark>
   </revision>
   <revision>
@@ -1348,9 +1349,9 @@ This approach  enables flexible support of multiple clients for a MIX channel pa
     from='hag66@shakespeare.example/UUID-a1j/7533'
     to='coven@mix.shakespeare.example'
     id='7nve413p'>
-  <query xmlns='urn:xmpp:mix:0'>
+  <setnick xmlns='urn:xmpp:mix:0'>
     <nick>thirdwitch</nick>
-  </query>
+  </setnick>
 </iq>
 ]]></example>
 
@@ -1363,9 +1364,9 @@ This approach  enables flexible support of multiple clients for a MIX channel pa
     from='coven@mix.shakespeare.example'
     to'hag66@shakespeare.example/UUID-a1j/7533'
     id='7nve413p'>
-  <query xmlns='urn:xmpp:mix:0'>
+  <setnick xmlns='urn:xmpp:mix:0'>
     <nick>thirdwitch</nick>
-  </query>
+  </setnick>
 </iq>
 ]]></example>
     </section3>