Fix several typos

Closes #1674.

readthedocs/examples/users.rst

@@ -71,4 +71,4 @@ through :tl:`UploadProfilePhoto`:
 
     await client(UploadProfilePhotoRequest(
         await client.upload_file('/path/to/some/file')
-    )))
+    ))

readthedocs/misc/changelog.rst

@@ -32,7 +32,7 @@ the project and would be a big undertaking.
 However, that doesn't mean calls are not possible with Telethon. If you want
 to help design a Python library to perform audio calls, which can then be used
 with Telethon (so you can use Telethon + that new library to perform calls
-with Telethon), please refer to `@pytgcallschat <https://t.me/@pytgcallschat/>`__
+with Telethon), please refer to `@pytgcallschat <https://t.me/pytgcallschat/>`__
 and join the relevant chat to discuss and help with the implementation!
 
 The above message was also `posted in the official Telegram group