keybase chat delete-history when user reset their profile

When a user (or one of multiple users in a multi-person chat) reset their profile the conversation has 2 versions and the following message displays:

```
reset their profile
Their encryption keys were replaced with new ones.
Jump to new conversation
```

When running:
```
keybase chat delete-history --private
```

Keybase is unable to delete this history for the old conversation. In fact you get the following response:

```
ERROR no conversation found
```

Also it doesn't seem like `keybase chat ls` works correctly as it returns `no conversations` when I only have ones left where a person has reset their profile.

Start by reproducing the profile-reset scenario, then run `keybase chat delete-history --private ` and `keybase chat ls` against the remaining conversations. Trace the conversation lookup used by these commands; done means old-conversation history can be deleted and `chat ls` reports conversations after a profile reset.

Written by the indexing model from the issue text.