Use hubot-xmpp fork

Fixes a bug which prevents it from working with chat.kosmos.org

package-lock.json

@@ -1854,9 +1854,8 @@
       }
     },
     "hubot-xmpp": {
-      "version": "0.2.5",
-      "resolved": "https://registry.npmjs.org/hubot-xmpp/-/hubot-xmpp-0.2.5.tgz",
-      "integrity": "sha1-/8PfqqejTVSz2SPqcWcRLErcnB0=",
+      "version": "github:67P/hubot-xmpp#acd71c36486c48a91e75e91bb58a436a2b8de03b",
+      "from": "github:67P/hubot-xmpp#dev",
       "requires": {
         "node-xmpp-client": "3.0.0",
         "uuid": "2.0.2"