MatrixClient is not stopped when the token no longer works

[turt2live]

This results in us hitting /versions, /pushrules, and /sync with no success because the token doesn't work. /pushrules is called on a loop to try and get them, which invokes calls on /versions. /sync just happens.

We should stop the MatrixClient when we know there's no hope in syncing.

[turt2live]

This also affects people's ability to log in. They'll get "Unable to connect to homeserver" because the /pushrules is 429ing. We do not back off when we receive a 429, but we should.

[shirishag75]

I saw the same thing. I guess the only sane thing remaining is to just read matrix's twitter handle and when things are a bit more saner try again. Although I won't be till downloads and esp. package repos. are not back. That probably will take another 1-2 days or more.

[turt2live]

As a bit more information: The client has to be offline when the token is deactivated. If the client is online, it stops making requests.

So to reproduce:

1. Log in
2. Delete your access token from the synapse database
3. Close riot
4. Restart synapse
5. Open riot