Re-enable flipper:// support

Summary: We used to support invoking `flipper://` to launch Flipper. This broke with the recent changes to our deeplink handling.

Reviewed By: mweststrate

Differential Revision: D31826699

fbshipit-source-id: 09d0d16de4779bb550da884d268ca9fd60f1a9e2

desktop/app/src/deeplink.tsx

@@ -43,6 +43,10 @@ export async function handleDeeplink(
   if (uri.protocol !== 'flipper:') {
     throw unknownError();
   }
+  if (uri.href === 'flipper://') {
+    // We support an empty protocol for just opening Flipper from anywhere.
+    return;
+  }
   if (uri.href.startsWith('flipper://open-plugin')) {
     return handleOpenPluginDeeplink(store, query, trackInteraction);
   }