Bot timeout on conversationUpdate request should result in 502 instead of 401

[compulim]

Related to microsoft/BotFramework-WebChat#2409.

Repro steps:

1. Start a conversation and post an activity, e.g. in Web Chat
2. The bot should receive conversationUpdate activity HTTP request before any user-originated activity
3. Instead of returning the HTTP response, let the request time out

Expected:

POST to directline.botframework.com/.../conversations/<cid>/activities should return 502 Gateway Timeout.

Actual:

We received 401 Unauthorized.

Additional context:

We are unsure if an "enhanced" token is used. We are sure it is a token generated via Direct Line channel.

[NickEricson]

Thank you for reporting this issue. We should have a fix deployed in the next few weeks. We will revert to the original behavior.

[NickEricson]

A fix was deployed world wide for this last week. Please let me know if you are still seeing this issue.