[webhook] Fix referencing options
[webhook] Fix referencing options

Bug:

  The confusion between using 'options' (passed by caller)
  and 'this.options' (cached on the object), we were making
  the assumption 'options.https' is unchanged!

  It's references is changed already as we had earlier assigned
  'this.options' to point to 'options', thus same object.

yagop/node-telegram-bot-api