Uncorrect NS on error #response{}

When ecomponent receives a stanza reply, the '#params.ns' is not the same depending if the reply is a "result" or an "error".

In case of a 'result' stanza, '#params.ns' is the NS from the first child element.

In case of an 'error' stanza, '#params.ns' is 'jabber:component:accept'.
