always truncate the filename (fix #1547)

src/core/bg/autosave.js

@@ -152,7 +152,7 @@ async function saveContent(message, tab) {
 		options.incognito = tab.incognito;
 		options.tabId = tabId;
 		options.tabIndex = tab.index;
-		options.keepFilename = options.saveToGDrive || options.saveToGitHub || options.saveWithWebDAV || options.saveToDropbox || options.saveToRestFormApi || options.saveToS3;
+		saveToRestFormApi || options.saveToS3;
 		let pageData;
 		try {
 			if (options.autoSaveExternalSave) {

src/core/content/content.js

@@ -195,7 +195,7 @@ async function savePage(message) {
 async function processPage(options) {
 	const frames = singlefile.processors.frameTree;
 	let framesSessionId;
-	options.keepFilename = options.saveToGDrive || options.saveToGitHub || options.saveWithWebDAV || options.saveToDropbox || options.saveToRestFormApi || options.saveToS3;
+	saveToRestFormApi || options.saveToS3;
 	singlefile.helper.initDoc(document);
 	ui.onStartPage(options);
 	processor = new singlefile.SingleFile(options);