remove objects and embed tags only if they have a source URL

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

@@ -371,7 +371,7 @@ this.SingleFileCore = this.SingleFileCore || (() => {
 		}
 
 		removeDiscardedResources() {
-			const objectElements = this.doc.querySelectorAll("applet, meta[http-equiv=refresh], object:not([type=\"image/svg+xml\"]):not([type=\"image/svg-xml\"]):not([type=\"text/html\"]), embed:not([src*=\".svg\"])");
+			const objectElements = this.doc.querySelectorAll("applet, meta[http-equiv=refresh], object[data]:not([type=\"image/svg+xml\"]):not([type=\"image/svg-xml\"]):not([type=\"text/html\"]), embed[src]:not([src*=\".svg\"])");
 			this.stats.set("discarded", "objects", objectElements.length);
 			this.stats.set("processed", "objects", objectElements.length);
 			objectElements.forEach(element => element.remove());