[Glitch] Fix unnecessary service worker registration and preloading when logged out

Port 894ce3726a to glitch-soc

Signed-off-by: Claire <claire.github-309c@sitedethib.com>

app/javascript/flavours/glitch/main.js

@@ -25,17 +25,17 @@ function main() {
         import('flavours/glitch/initial_state'),
       ]);
 
-      const wb = new Workbox('/sw.js');
+      if (me) {
+        const wb = new Workbox('/sw.js');
 
-      try {
-        await wb.register();
-      } catch (err) {
-        console.error(err);
+        try {
+          await wb.register();
+        } catch (err) {
+          console.error(err);
 
-        return;
-      }
+          return;
+        }
 
-      if (me) {
         const registerPushNotifications = await import('flavours/glitch/actions/push_notifications');
 
         store.dispatch(registerPushNotifications.register());