take into account ignored URLs in srcset

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

@@ -1326,6 +1326,8 @@ this.SingleFileCore = this.SingleFileCore || (() => {
 						} else {
 							return "";
 						}
+					} else {
+						return resourceURL + (srcsetValue.w ? " " + srcsetValue.w + "w" : srcsetValue.d ? " " + srcsetValue.d + "x" : "");
 					}
 				}));
 				resourceElement.setAttribute(attributeName, srcsetValues.join(", "));