Groups inside modifiers create orphan fieldsets

[jtojnar]

When group is created inside the modifier, clicking the create button will cause one more fieldset to be created than there are containers:

  <form action="/" method="post" id="frm-form">
  
  <fieldset>
  <legend>Team member #1</legend>
  
  <table>
  <tr>
  	<th><label for="frm-form-members-0-name">Name</label></th>
  
  	<td><input type="text" name="members[0][name]" id="frm-form-members-0-name" class="text"></td>
  </tr>
  </table>
  </fieldset>
  
  <fieldset>
  <legend>Team member #2</legend>
  
  <table>
  <tr>
  	<th><label for="frm-form-members-1-name">Name</label></th>
  
  	<td><input type="text" name="members[1][name]" id="frm-form-members-1-name" class="text"></td>
  </tr>
  </table>
  </fieldset>
  
  <fieldset>
  <legend>Team member #3</legend>
  </fieldset>
  
  <table>
  <tr>
  	<th></th>
  
  	<td><input type="submit" name="members[multiplier_creator]" class=" button" value="add" formnovalidate data-nette-validation-scope='["members"]'></td>
  </tr>
  </table>
  
  <input type="hidden" name="_do" value="form-submit">
  </form>

See #83 for a test.