title: dropzone doesnt upload some pictures (internal server error 500)
body: <p>i use dropzone for file(images) upload. when i upload on my local computer, files upload successfully. but when i upload files on my web host, dropzone gives iternal server error on some pictures(not for all). just for experiment, i uploaded one picture several times. and sometimes dropzone gives an error, and sometime doesnt(on the same picture). not to blame picture's size (i also tried pictures about 4-5 kb). here's my code</p>
  
  <pre><code> Dropzone.autoDiscover = false;
  var myDropzone = new Dropzone("div#dropZone",  { url: "{{action('AdminToursController@storeImage')}}",
      addRemoveLinks : true
  } );
  myDropzone.on('sending', function(file, xhr, formData){
      formData.append("_token", $('meta[name="csrf_token"]').attr('content')); // Laravel expect the token post value to be named _token by default
  
  });
  var i = 1;
  myDropzone.on('complete', function(a, b, c){
      var src = JSON.parse(a.xhr.responseText).uploaded_path;
      $("&lt;input type='hidden' name='gallery-img-" + i++ + "' value='"+ src + "'/&gt;").appendTo('.tour-add-form');
      addRemoveLinks : true;
  });
  </code></pre>