added missing use of Token class

lib/single-file/css-declarations-parser.js

@@ -581,7 +581,7 @@ this.parseCss = this.parseCss || (() => {
 		tokenAt(i) {
 			if (i < this.tokens.length)
 				return this.tokens[i];
-			return { tokenType: EOF_TOKEN_TYPE };
+			return new Token(EOF_TOKEN_TYPE);
 		}
 		consume(num) {
 			if (num === undefined)