Disable http range requests in pdf.js.

A bug in pdf.js or Chrome is causing pdf books to not load.

TNL-488

lms/djangoapps/staticbook/views.py

@@ -106,7 +106,7 @@ def pdf_index(request, course_id, book_index, chapter=None, page=None):
         viewer_params += current_chapter['url']
         current_url = current_chapter['url']
 
-    viewer_params += '#zoom=page-fit'
+    viewer_params += '#zoom=page-fit&disableRange=true'
     if page is not None:
         viewer_params += '&page={}'.format(page)
 

lms/templates/static_pdfbook.html

@@ -18,7 +18,7 @@ $(function(){
     e.preventDefault();
     var url = $(this).attr('rel');
     $('#viewer-frame').attr({
-        'src': '${request.path}?viewer=true&file=' + url + '#zoom=page-fit',
+        'src': '${request.path}?viewer=true&file=' + url + '#zoom=page-fit&disableRange=true',
         'title': $(this).text()
         });
     $('#viewer-frame').focus();