added try/finally when calling downloadPage

extension/core/bg/autosave.js

@@ -125,8 +125,11 @@ singlefile.extension.core.bg.autosave = (() => {
 		await processor.run();
 		const page = await processor.getPageData();
 		page.url = URL.createObjectURL(new Blob([page.content], { type: "text/html" }));
-		await singlefile.extension.core.bg.downloads.downloadPage(page, options);
-		URL.revokeObjectURL(page.url);
+		try {
+			await singlefile.extension.core.bg.downloads.downloadPage(page, options);
+		} finally {
+			URL.revokeObjectURL(page.url);
+		}
 	}
 
 })();