refactor: fix typo

Closes socketio/socket.io-client#1354

Author: darrachequesne

lib/transports/polling-xhr.js

@@ -228,7 +228,7 @@ class Request extends Emitter {
       debug("xhr data %s", this.data);
       xhr.send(this.data);
     } catch (e) {
-      // Need to defer since .create() is called directly fhrom the constructor
+      // Need to defer since .create() is called directly from the constructor
       // and thus the 'error' event can only be only bound *after* this exception
       // occurs.  Therefore, also, we cannot throw here at all.
       setTimeout(function() {