Fix timeout for sync request

[slipeer]

Fix for: #131

According Requests doc it accept timeout parameter in seconds.
But in api.py#L78 to this parameter passed huge value 30000 sec = 8.3 hours from api.py#L63
I think line api.py#L78 must be like: "timeout": timeout_ms/1000.0

[matrixbot]

Can one of the admins verify this patch?

[non-Jedi]

This should address the specific problem the user had with /sync in #129, but
we should also implement a general timeout for all requests. @slipeer, could you
sign-off on this per
https://github.com/matrix-org/matrix-python-sdk/blob/master/CONTRIBUTING.rst#sign-off

[slipeer]

Sorry, I've been waiting for more than three months to respond to a one-line editing of a typo that causes significant problems with timeouts. Apparently this project is sooner dead and I'm not ready to spend time on a project that no one needs.

[non-Jedi]

@slipeer sorry to hear that. The maintainer for this project has been too
busy to accepept PRs for a few months. Just today I've stepped in for him as
a co-maintainer, so this shouldn't happen in the future.

Thanks for taking the time to make the PR, and sorry you had a bad
experience.