[keel] Cleanup ox::Error(0) instance

src/olympic/keel/include/keel/assetmanager.hpp

@@ -154,7 +154,7 @@ class AssetRef: public ox::SignalHandler {
 	private:
 		constexpr ox::Error emitUpdated() const noexcept {
 			updated.emit();
-			return ox::Error(0);
+			return {};
 		}
 };