Fix missing layout call after switching repos

This didn't cause a bug so far because switching repos always happens from
within an OnWaitingStatus, so the spinner would take care of calling layout and
draw. However, later in this branch we are going to optimize the spinner so that
it no longer calls layout, at which point this would break, so make sure we
rerender at the point where it's needed.

pkg/gui/gui.go

@@ -428,6 +428,8 @@ func (gui *Gui) onNewRepo(startArgs appTypes.StartArgs, contextKey types.Context
 
 	gui.c.Context().Push(contextToPush, types.OnFocusOpts{})
 
+	gui.render()
+
 	return nil
 }