Fix refresh btn issue

Author: z-song

src/Widgets/Navbar.php

@@ -67,14 +67,14 @@ public function add($element)
      */
     public function render($part = 'right')
     {
-        if (!isset($this->elements[$part]) || $this->elements[$part]->isEmpty()) {
-            return '';
-        }
-
         if ($part == 'right') {
             $this->right(new RefreshButton());
         }
 
+        if (!isset($this->elements[$part]) || $this->elements[$part]->isEmpty()) {
+            return '';
+        }
+
         return $this->elements[$part]->map(function ($element) {
             if ($element instanceof Htmlable) {
                 return $element->toHtml();