Checklist

• I am sure the error is coming from Pyrogram's code and not elsewhere.
• I have searched in the issue tracker for similar bug reports, including closed ones.
• I ran pip3 install -U https://github.com/pyrogram/pyrogram/archive/develop.zip and reproduced the issue using the latest development version.

Description

File pyrogram\client\methods\chats\get_dialogs.py
In get_dialogs function:

...
for message in r.messages:
    to_id = message.to_id
...

MessageEmpty type is ignored here.

It should be something like this::

...
for message in r.messages:
    if isinstance(message, types.MessageEmpty):
        continue

    to_id = message.to_id
...

Traceback

Traceback (most recent call last):
  File "main.py", line 28, in main
    for dialog in app.iter_dialogs():
  File "C:\Python36\site-packages\pyrogram\client\methods\chats\iter_dialogs.py", line 75, in iter_dialogs
    limit=limit
  File "C:\Python36\site-packages\pyrogram\client\methods\chats\get_dialogs.py", line 87, in get_dialogs
    to_id = message.to_id
AttributeError: 'MessageEmpty' object has no attribute 'to_id'