fixed simple quotes issue

Former-commit-id: dbb8185c8a655b7e86527fb2cd767eb6d8dad6d4

lib/single-file/modules/html-serializer.js

@@ -129,13 +129,13 @@ this.singlefile.lib.modules.serializer = this.singlefile.lib.modules.serializer
 		let content = "";
 		if (!name.match(/["'>/=]/)) {
 			let value = attribute.value;
-			if (name == "class") {
+			if (compressHTML && name == "class") {
 				value = Array.from(element.classList, className => className.trim()).join(" ");
 			}
 			let simpleQuotesValue;
 			value = value.replace(/&/g, "&").replace(/\u00a0/g, " ");
 			if (value.includes("\"")) {
-				if (value.includes("'") || compressHTML) {
+				if (value.includes("'") || !compressHTML) {
 					value = value.replace(/"/g, """);
 				} else {
 					simpleQuotesValue = true;