Fix cancelled save blocking next ones (Firefox)

extension/core/bg/download.js

@@ -98,7 +98,9 @@ singlefile.download = (() => {
 					return downloadPage(page, { confirmFilename: options.confirmFilename, filenameConflictAction: options.filenameConflictAction });
 				} else if (errorMessage == "conflictaction prompt not yet implemented" && options.filenameConflictAction) {
 					return downloadPage(page, { confirmFilename: options.confirmFilename });
-				} else if (!errorMessage.includes("canceled")) {
+				} else if (errorMessage.includes("canceled")) {
+					return Promise.resolve({});
+				} else {
 					throw error;
 				}
 			} else {