title: python-telegram-bot ERROR 'CallbackContext' object has no attribute 'message'
body: <p>Below is an example of the telegram bot.
  Help me understand why function <strong><em>message_handler</em></strong> works in my code, and <strong><em>greet_user</em></strong> - not working.</p>
  
  <p>There is a error from error_log decorator: <code>'CallbackContext' object has no attribute 'message'</code></p>
  
  <pre><code>from telegram import Update, Bot
  from telegram.ext import Updater, MessageHandler, Filters, CallbackContext, CommandHandler
  from telegram.utils.request import Request
  
  
  def log_error(func):
      def wrapper(*args, **kwargs):
          try:
              return func(*args, **kwargs)
          except Exception as exc:
              print(f'Error: {exc}')
              raise exc
  
      return wrapper
  
  
  def message_handler(update: Update, context: CallbackContext):
      update.message.reply_text(text='Example')
  
  
  @log_error
  def greet_user(bot, update):
      update.message.reply_text('hello')
  
  def main():
      req = Request(connect_timeout=0.5)
      t_bot = Bot(
          request=req,
          token='xxxxxxxxxxxxxxxxxxxxxxxxxxxx',
          base_url='https://telegg.ru/orig/bot',
      )
      updater = Updater(bot=t_bot, use_context=True)
  
      dp = updater.dispatcher
      dp.add_handler(CommandHandler('start', greet_user))
      dp.add_handler(MessageHandler(filters=Filters.all, callback=message_handler))
  
      updater.start_polling()
      updater.idle()
  
  if __name__ == '__main__':
      main()
  </code></pre>