change instanceof to Array.isArray()

Author: leaves4j

lib/renderer.js

@@ -276,7 +276,7 @@ class Renderer extends EventEmitter {
     const keys = ['title', 'titleTemplate', 'htmlAttrs', 'bodyAttrs', 'base', 'meta', 'link', 'style', 'script', 'noscript'];
     keys.forEach(key => {
       if (head[key] && baseHead[key]) {
-        if (baseHead[key] instanceof Array) {
+        if (Array.isArray(baseHead[key])) {
           newHead[key] = [];
           baseHead[key].forEach(item => newHead[key].push(item));
           head[key].forEach(item => newHead[key].push(item));