removed unneeded call to Promise#then

lib/single-file/single-file-core.js

@@ -222,19 +222,18 @@ this.SingleFileCore = this.SingleFileCore || (() => {
 			});
 			let parallelTasksPromise;
 			if (STAGES[step].parallel) {
-				parallelTasksPromise = await Promise.all(STAGES[step].parallel.map(task => {
+				parallelTasksPromise = await Promise.all(STAGES[step].parallel.map(async task => {
 					let startTime;
 					if (DEBUG) {
 						startTime = Date.now();
 						log("  // STARTED task =", task.action);
 					}
 					this.onprogress(new ProgressEvent(STAGE_TASK_STARTED, { pageURL: this.options.url, step, task: task.action, frame }));
-					const promise = this.executeTask(task);
-					promise.then(() => this.onprogress(new ProgressEvent(STAGE_TASK_ENDED, { pageURL: this.options.url, step, task: task.action, frame })));
+					await this.executeTask(task);
+					this.onprogress(new ProgressEvent(STAGE_TASK_ENDED, { pageURL: this.options.url, step, task: task.action, frame }));
 					if (DEBUG) {
-						promise.then(() => log("  // ENDED task =", task.action, "delay =", Date.now() - startTime));
+						log("  // ENDED task =", task.action, "delay =", Date.now() - startTime);
 					}
-					return promise;
 				}));
 			} else {
 				parallelTasksPromise = Promise.resolve();