title: Missing upload related browse option in tinymce
body: <p>I'm working on tinymce rich text editor.
  I had used the fileupload option in menu of rich text.
  Unfortunately I was not ale to get the browse option for the file upload pop-up window.</p>
  
  <p><a href="https://i.stack.imgur.com/yINZZ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/yINZZ.png" alt="Without browse option"></a></p>
  
  <p>Expected Result :
  taken from <a href="https://codepen.io/nirajmchauhan/pen/EjQLpV" rel="nofollow noreferrer">https://codepen.io/nirajmchauhan/pen/EjQLpV</a>
  <a href="https://i.stack.imgur.com/WFqQe.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/WFqQe.png" alt="Expected result"></a></p>
  
  <p>My code :</p>
  
  <pre><code>function loadTinyMCEEditor() {
          tinyMCE.init({
              selector: "textarea",
              theme: "modern",
              menu: { // this is the complete default configuration
                  file: { title: 'File', items: 'newdocument' },
                  edit: { title: 'Edit', items: 'undo redo | cut copy paste pastetext | selectall' },
  
                  insert: { title: 'Insert', items: 'link media | template hr' },
                  view: { title: 'View', items: 'visualaid' },
                  format: { title: 'Format', items: 'bold italic underline strikethrough superscript subscript | formats | removeformat' },
  
                  tools: { title: 'Tools', items: 'spellchecker code' }
              },
              plugins: [
    "advlist autolink lists link image charmap print preview hr anchor pagebreak",
    "searchreplace wordcount visualblocks visualchars code fullscreen",
  
              ],
              toolbar1: "insertfile undo redo | styleselect | bold italic | alignleft aligncenter alignright alignjustify | bullist numlist outdent indent | link image",
  
              toolbar_items_size: 'small',
              setup: function (ed) {
                  ed.on('blur', function (x,e) {
                      debugger;
                      var x = $(x.target.editorContainer).find('iframe')[0];
                      var idis = $(x).attr('id');
                      var fields = idis.split('_');
  
                      var bp = fields[2];
                      var bplevel = fields[3];
                      tinyMCE.triggerSave();
                      var doc = document.getElementById(idis).contentDocument;
                      var g = doc.all[0]
                      var val = g.innerHTML
                      AutoSaveLevel(val, bp, bplevel);
                      console.log('blur event fired.');
                  });
              }
          });
      }
  </code></pre>