Double warning for proxies on export

[Nick Lear]

This has been in the main version and the Beta for months - a double warning (in different fonts) for exporting with proxies present when going to the export page from the edit page.

To be fair, at one point there was a triple warning so there is some progress 🙂

The first warning is on the edit page and the second on the export page 

Win 10, Pr Beta 24.0.0 b14