Fix SparkAR connection

Summary:
Changelog: Fixed skyline no longer connecting to Flipper

Per https://fb.workplace.com/groups/flippersupport/permalink/1214902038990452/. Reverts a change introduced here: https://www.internalfb.com/diff/D30838947 (d8f77db632)?transaction_fbid=439205157417044

Reviewed By: lblasa

Differential Revision: D30992087

fbshipit-source-id: 529f473807b53137b20fd39c37be95e6d7ec0c6d

desktop/app/src/server/utils/CertificateProvider.tsx

@@ -312,7 +312,11 @@ export default class CertificateProvider {
         destination + filename,
         contents,
       );
-    } else if (os === 'iOS') {
+    } else if (
+      os === 'iOS' ||
+      os === 'windows' ||
+      os == 'MacOS' /* Used by Spark AR?! */
+    ) {
       try {
         await fs.writeFile(destination + filename, contents);
       } catch (err) {