[toc2] Restore cells to original width, see #993, following @jcb91

Author: jfbercher

src/jupyter_contrib_nbextensions/nbextensions/toc2/toc2.js

@@ -177,15 +177,15 @@ var make_link = function(h, num_lbl) {
                 $('#notebook-container').css('margin-left', 30);
                 $('#notebook-container').css('width', $('#notebook').width() - 30);
             } else { // original width
-              $("#notebook-container").css({'width':st.nbcontainer_width, 'margin-left':'auto'})             
+              $("#notebook-container").css({'width':'', 'margin-left':'auto'})             
             }
         }
     } else {
         if (cfg.widenNotebook) {
             $('#notebook-container').css('margin-left', 30);
             $('#notebook-container').css('width', $('#notebook').width() - 30);
         } else { // original width
-            $("#notebook-container").css({'width':st.nbcontainer_width, 'margin-left':'auto'})
+            $("#notebook-container").css({'width':'', 'margin-left':'auto'})
         }
     }
 }