Updated chat/ejabberd to 2.0.5

* Fix two problems introduced in ejabberd 2.0.4: subscription request produced
  many authorization requests with some clients and transports; and
  subscription requests were not stored for later delivery when receiver was
  offline.
* Fix warning in expat_erl.c about implicit declaration of x_fix_buff
* HTTP-Bind (BOSH): Fix a missing stream:error in the returned
  remote-stream-error stanza

(martti)