do not answer to adhoc command discovery queries

Hi,

I discovered by accident that djabberd answer to all
discovery query, even those
for adhoc command ( XEP 0050 ), and it was giving weird
result with my jabber
client ( a empty list instead of the usaul message "the
server do not support
XXX" ).

Basically, my client sent this :
<iq to="example.org" type="get"
id="218" from="miscexample.org/Gajim">
<query xmlns="http://j
abber.org/protocol/disco#items"
node="http://jabb
er.org/protocol/commands" />
</iq>

and djabberd should not answer to such queries, and instead,
it answered this :

<iq to='miscexample.org/Gajim' from='example.org'
type='result' id='218'>
<query xmlns='http://jabber.
org/protocol/disco#items'>
<item jid='chat.example.org' name='' />
</query>
</iq>

Obviously, it answer as if the query was a normal one.
So I filled a bug against the client ( http://trac.gajim.o
rg/ticket/3460 ), and
I propose the following patch to djabberd.

-- 
Michael Scherer