fixed undefined options

Former-commit-id: fb75450cdbd9a4c689606b8621e4eca1e173c656

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

@@ -153,7 +153,7 @@ this.singlefile.lib.core = this.singlefile.lib.core || (() => {
 
 	class Runner {
 		constructor(options, root) {
-			const rootDocDefined = root && this.options.doc;
+			const rootDocDefined = root && options.doc;
 			this.root = root;
 			this.options = options;
 			this.options.url = this.options.url || (rootDocDefined && this.options.doc.location.href);