Occasionally, the "summarize conversation" prompt above is ignored

[radman-x]

Occasionally, the "summarize conversation ..." prompt above is ignored; usually it works after repeating it again. However, this must be fixed.
Appears this is due to the GroupChatManager determining that the user_proxy (eg, "Admin") should be the speaker two times in a row. So, this can be solved by setting allow_repeat_speaker to a list of all agents except the Admin.