bring back OsPath changes

I hope that the windows test suite failure on appveyor was fixed by
updating to a newer windows there. I have not been able to reproduce
that failure in a windows 11 VM run locally.

Utility/WebApp.hs

@@ -187,7 +187,9 @@ insertAuthToken extractAuthToken predicate webapp root pathbits params =
  - to avoid exposing the secret token when launching the web browser. -}
 writeHtmlShim :: String -> String -> FilePath -> IO ()
 writeHtmlShim title url file = 
-	viaTmp (writeFileProtected . toRawFilePath) file $ genHtmlShim title url
+	viaTmp (writeFileProtected . fromOsPath)
+		(toOsPath $ toRawFilePath file) 
+		(genHtmlShim title url)
 
 genHtmlShim :: String -> String -> String
 genHtmlShim title url = unlines