Since Scalar (and other integration managers) are loaded as apps into
an iframe, a valid `scalar_token` must exist when loading the app.
It is possible that a scalar_token becomes invalid between the time
when the integration manager button was rendered and the user clicking
the link. Here we make a call to integration manager `/account`
before trying to render the integration manager, which ensures we
have a valid token for the integration manager to work with.
Moving the scalar token revalidation to the cases where it is actually
needed could make it possible to decrease the amount of Scalar /account
calls we do when switching rooms, which is currently 3.
Signed-off-by: Jason Robinson <jasonr@matrix.org>
