wait until "load" event by default when run in headless mode

cli/back-ends/webdriver-chrome.js

@@ -101,7 +101,7 @@ exports.getPageData = async options => {
 			await driver.executeAsyncScript(scripts + "\naddEventListener(\"single-file-network-idle-0\", () => arguments[0](), true)");
 		} else if (!optionHeadless && options.browserWaitUntil == "networkidle2") {
 			await driver.executeAsyncScript(scripts + "\naddEventListener(\"single-file-network-idle-2\", () => arguments[0](), true)");
-		} else if (options.browserWaitUntil == "load") {
+		} else if (optionHeadless || options.browserWaitUntil == "load") {
 			await driver.executeAsyncScript(scripts + "\nif (document.readyState == \"loading\") { document.addEventListener(\"load\", () => arguments[0]()) } else { arguments[0](); }");
 		} else {
 			await driver.executeScript(scripts);