mod_delegation: use clean_xmlns to remove jabber:client namespace from node: for the same reason as in mod_privilege, `jabber:client` namespace is removed with the clean_xmlns method coming from there. Furthermore, the forwarded <iq> stanza use the `jabber:client` xmlns while the stanza may come from a component with e.g. `jabber:component:accept` xmlns, this can lead to inconsistencies between the <iq> stanza and children (like <error> element).

[Install]
WantedBy=sockets.target

[Socket]
ListenStream=0.0.0.0:5222
ListenStream=5222
BindIPv6Only=ipv6-only
Accept=false
Service=prosody.service