title: DropzoneJS limit selecting of files to one file but allow subsequent uploads
body: <p>I am trying to limit the number of files a user can select to one using the option maxFiles: 1; however that also prevents the user from uploading a second, third etc. file which is what I want. I want only the selection to be limited to one file and allow for subsequent uploads. Is that possible?</p>
  
  <p>Here is my code:</p>
  
  <pre><code>$(function() {
      var dropzone = new Dropzone('#avatar-wrapper', {
          url: '/uploads/avatar',
          clickable: '.upload',
          maxFilesize: 5,
          maxFiles: 1,
          previewsContainer: false,
          headers: {
              'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')
          },
          init: function() {
              this.on('addedfile', function(file) {
                  console.log('test');
                  $('#loader').show();
              });
  
              this.on('success', function(file, result) {
                  $('#avatar_url').val(result.url);
                  $('#avatar').attr('src', result.url);
                  $('#loader').hide();
              });
          }
      });
  });
  </code></pre>