Autoprop has a timer that checks whether we're on a new/different runtime
periodically. When we detect we are, we re-build the props, so that they may
be re-published under that new version identifier.
However, we weren't updating the cached runtime version we store in state,
causing every firing of this timer to re-build the props.
Here, we correctly update state if we detect a difference, so that subsequent
timers don't trigger redundant rebuilds.
