ijbridge: Add nick address to jabber WHOIS return

Currently it is not possible from jabber to determine the host from which an IRC user is logged in (the host field is usually empty) This makes it impossible to check if an IRC user might be a well known troll.

However the response 311 on the WHOIS request does contain the required info. Therefore I request an additional line Address: is added to the return.

The following changes should be enough to add this:

In proc client::registerhandlers

# change the 311 registerevent to (I was unable to test if [additional] is what's needed:
$cn registerevent 311 {
set ::client::whois(realname) [msg]
set ::client::whois(address) [additional]
}

# and in the 318 registerevent add:
append info "Address: $whois(address)"