in_reply_to doesn't work with telegram backend

[luginbash]

Is your feature request related to a problem? Please describe.
What I wanted to do is:

class TestPlugin(BotPlugin):
  @botcmd
  def testcmd(self, msg: Message, _):
    self.send(self.build_identifier(msg.frm.room.id), text=_text, in_reply_to=msg.parent)

I noticed that msg.parent is always None with telegram backend, so i added it in a branch:

master...luginbash:errbot:luginbash/feature/telegram-msg-parent

Afterwards, the bot is able to get the parent of the message, but when viewing in telegram, it's not replying to the message it was referred to.

I tried to trace how BotPlugin calls bot.send() but it was a bit too complex, I think it would be easier for the authors to point out the links.

Describe the solution you'd like
A clear and concise description of what you want to happen.

Is feature related to

• Backend support
• Plugins (storage, flows)
• Functionality
• Other

Additional context
Any help would be ... helpful!