Fix issue with tryPutBeforeUpdating

LeStorage/StoredSingleton.swift

@@ -27,10 +27,11 @@ public class StoredSingleton<T: SyncedStorable>: SyncedCollection<T> {
         return self.items.first
     }
     
-    @discardableResult public func tryPutBeforeUpdating(_ instance: T) async throws -> T? {
+    public func tryPutBeforeUpdating(_ instance: T) async throws {
         let result = try await StoreCenter.main.service().rawPut(instance)
-        self.setItemNoSync(result)
-        return result
+        if let item = self.item() {
+            item.copy(from: result)
+        }
     }
     
     // MARK: - Protects from use