fix：目录有关问题 (#931)

Author: 0fuling0

layout/_widget/toc.ejs

@@ -1,9 +1,10 @@
 <%- partial('_pre') %>
 <% var realcontent = (page.encrypt == true) ? page.origin : page.content; %>
-
+<% if (realcontent && page.toc != false && toc(realcontent).length > 0) { %>
 <section class="widget toc-wrapper <%- page.widget_platform %>" id="toc-div" <% if (page.encrypt == true) { %>style="display:none" <% } %>>
   <%- partial('header', {item: item}) %>
   <div class='content'>
       <%- toc(realcontent, {list_number: item.list_number, min_depth: item.min_depth, max_depth: item.max_depth}) %>
   </div>
 </section>
+<% } %>