Connection: add comment about OAUTH + SASL-IR

lib/Connection.js

@@ -1208,13 +1208,14 @@ Connection.prototype._login = function() {
       if (self.serverSupports('AUTH=XOAUTH') && self._config.xoauth) {
         self._caps = undefined;
         var cmd = 'AUTHENTICATE XOAUTH';
-        if (self.serverSupports('SASL-IR'))
+        // are there any servers that support XOAUTH/XOAUTH2 and not SASL-IR?
+        //if (self.serverSupports('SASL-IR'))
           cmd += ' ' + escape(self._config.xoauth);
         self._enqueue(cmd, checkCaps);
       } else if (self.serverSupports('AUTH=XOAUTH2') && self._config.xoauth2) {
         self._caps = undefined;
         var cmd = 'AUTHENTICATE XOAUTH2';
-        if (self.serverSupports('SASL-IR'))
+        //if (self.serverSupports('SASL-IR'))
           cmd += ' ' + escape(self._config.xoauth2);
         self._enqueue(cmd, checkCaps);
       } else if (self._config.user && self._config.password) {