Remove mention of SmartScreen

Seldom an issue now that the builds are codesigned, and the link
was broken.

src/platform/windows/installation-issues.md

@@ -11,10 +11,6 @@ Please also see [startup issues](./startup-issues.md).
 If closing Anki and your browser does not help, please try restarting your
 computer, then running the installer again.
 
-## "Windows protected your PC"
+## Antivirus issues
 
-When a new Anki version is released, Windows may display a scary-looking message
-until it has seen enough people using the new version. To be able to proceed
-with app installation, please use [Run anyway](https://www.tekrevue.com/tip/windows-protected-your-pc-disable-smartscreen/).
-
-Antivirus programs may sometimes also report a [false positive](https://faqs.ankiweb.net/my-antivirus-program-says-anki-is-infected.html).
+Antivirus programs may sometimes report a [false positive](https://faqs.ankiweb.net/my-antivirus-program-says-anki-is-infected.html).