title: ngb-tab [hidden]="tab.hidden" not work
body: <p>Why does not work [hidden] = "tab.hidden"?</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;ngb-tabset [activeId]="activeTab" (tabChange)="activeTab = $event.nextId"&gt;
          &lt;ngb-tab *ngFor="let tab of tabs" [id]="tab.id" [disabled]="tab.disabled" [hidden]="tab.hidden"&gt;
            &lt;ng-template ngbTabTitle&gt;{{tab.title}}&lt;/ng-template&gt;
            &lt;ng-template ngbTabContent&gt;
              &lt;p style="margin: 20px"&gt;Raw denim you probably haven't heard of them jean shorts Austin. Nesciunt tofu stumptown aliqua, retro synth
                master cleanse. Mustache cliche tempor, williamsburg carles vegan helvetica. Reprehenderit butcher retro keffiyeh
                dreamcatcher synth. Cosby sweater eu banh mi, qui irure terry richardson ex squid. Aliquip placeat salvia cillum
                iphone. Seitan aliquip quis cardigan american apparel, butcher voluptate nisi qui.&lt;/p&gt;
            &lt;/ng-template&gt;
          &lt;/ngb-tab&gt;
        &lt;/ngb-tabset&gt;</code></pre>
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  </div>
  </p>
  
  <p>M.</p>