title: Query string parameters duplicated every PJAX form update - 414 Request-URI Too Large
body: <p><strong>This is the ActiveForm with PJAX code in my view</strong>:</p>
  
  <pre><code>&lt;?php Pjax::begin(['enablePushState' =&gt; false, 'id' =&gt; 'pjax-container']); ?&gt;
  ...
  &lt;?php $form = ActiveForm::begin(['method' =&gt; 'POST',], ['options' =&gt; ['data-pjax' =&gt; true]]); ?&gt;
  &lt;?= $form-&gt;field($model, 'form_input_1')-&gt;dropDownList($items, $params)-&gt;label(false); ?&gt;
  ...
  &lt;?php ActiveForm::end(); ?&gt;
  ...
  &lt;?php echo ListView::widget([...]); ?&gt;
  ...
  &lt;?php Pjax::end(); ?&gt;
  </code></pre>
  
  <p><strong>And i update it by js</strong>: </p>
  
  <pre><code>$(document).on('change', 'filter dropdown_list', function(e) {
      $.pjax({
          push: false,
          timeout: 1000,
          url: $('#filter-form').attr('action'),
          container: '#pjax-conteiner',
          data: $('#filter-form').serializeArray(),
      });
  });
  </code></pre>
  
  <p>So, every new query, the string parameters duplicated.</p>
  
  <p><strong>Query String Parameters After first query</strong>:</p>
  
  <p><strong>_csrf</strong>:VXswIzZsAyI2aQ==</p>
  
  <p><strong>FormName[form_input_1]</strong>:1</p>
  
  <p><strong>FormName[form_input_1]</strong>:2</p>
  
  <p><strong>FormName[form_input_1]</strong>:3</p>
  
  <p><strong>_pjax</strong>:#pjax-container</p>
  
  <p><strong>Query String Parameters After second query:</strong></p>
  
  <p><strong>_csrf</strong>:VXswIzZsAyI2aQ==</p>
  
  <p><strong>FormName[form_input_1]</strong>:1</p>
  
  <p><strong>FormName[form_input_1]</strong>:2</p>
  
  <p><strong>FormName[form_input_1]</strong>:3</p>
  
  <p><strong>_pjax</strong>:#pjax-container</p>
  
  <p><strong>_csrf</strong>:VXswIzZsAyI2zZs==</p>
  
  <p><strong>FormName[form_input_1]</strong>:2</p>
  
  <p><strong>FormName[form_input_1]</strong>:3</p>
  
  <p><strong>FormName[form_input_1]</strong>:4</p>
  
  <p><strong>_pjax</strong>:#pjax-container</p>
  
  <p>And after, for example, 15 queries, i have this error: <strong>414 Request-URI Too Large</strong></p>
  
  <p>Whats wrong and how can i fix it?</p>