Fix issues with BOSH prebinding.
Fix issues with BOSH prebinding.

Some of the special numbers aren't included in BOSH responses outside of
the initial setup, so we can't rely on them being there when prebinding
is used.

otalk/stanza.io,Palid/stanza.io,legastero/stanza.io,legastero/stanza.io,Palid/stanza.io,otalk/stanza.io