fixed missing favicon issue

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

@@ -380,7 +380,10 @@ this.SingleFileCore = this.SingleFileCore || (() => {
 		}
 
 		insertFaviconLink() {
-			let faviconElement = this.doc.querySelector("link[href][rel*=\"icon\"]");
+			let faviconElement = this.doc.querySelector("link[href][rel=\"icon\"]");
+			if (!faviconElement) {
+				faviconElement = this.doc.querySelector("link[href][rel=\"shortcut icon\"]");
+			}
 			if (!faviconElement) {
 				faviconElement = this.doc.createElement("link");
 				faviconElement.setAttribute("type", "image/x-icon");