chore: remove the unused value in supabase_task (#3157)

frontend/appflowy_flutter/lib/startup/tasks/supabase_task.dart

@@ -18,7 +18,6 @@ import '../startup.dart';
 const appflowyDeepLinkSchema = 'appflowy-flutter';
 const supabaseLoginCallback = '$appflowyDeepLinkSchema://login-callback';
 
-bool isSupabaseInitialized = false;
 const hiveBoxName = 'appflowy_supabase_authentication';
 
 // Used to store the session of the supabase in case of the user switch the different folder.
@@ -31,10 +30,6 @@ class InitSupabaseTask extends LaunchTask {
       return;
     }
 
-    if (isSupabaseInitialized) {
-      return;
-    }
-
     // register deep link for Windows
     if (Platform.isWindows) {
       registerProtocolHandler(appflowyDeepLinkSchema);