Closing browser windows with the close button shuts down the client

[amylizzle]

Closing with the tgui close button is fine, but using the system window's close button shuts down the client.

Noticed on goon (closing the start popups) on ubuntu

[wixoaGit]

This bug comes from SDL version 3.4.0, which is the version RT's NuGet package uses. Newer versions of SDL fix this so an update to the package would fix it.

A workaround for now would be to connect from the launcher since that still uses SDL 3.2.0.