Clarify remote revision message in mobile app

[alstr]

When trying to view a remote revision in the iOS app I get an error:

"The remote revision could not be loaded. Please try again later."

I have just realised by checking on desktop that this is because of the plan I'm on:

"Version history is limited to the current session's changes in the free plan. Learn more about our other plans to upgrade your history capacity."

I would suggest updating the message in the iOS app as it reads more like a technical error.

As a side note the revisions seem a little confusing in general - under "Today" I see a date from last month. Whilst I kind of get it, it just could be a bit clearer I think.