Show a more helpul message when logging into an account with an empty timeline

[jp-hoehmann]

When there are no posts to load, the home screen will have a message telling the user no posts were found and that “the service may be temporarily unavailable”. Not sure whether this would me considered a bug, since it is not technically wrong, but it is the very first page a new user that just downloaded the app and created an account will see, and it is confusing and demotivating in that context.