omit unnecessary lines

lib/views/admin/customize.html

@@ -5,9 +5,7 @@
 {% block html_additional_headers %}
   {% parent %}
   <!-- CodeMirror -->
-  <link rel="stylesheet" href="https://cdn.jsdelivr.net/g/codemirror@4.5.0(codemirror.css+addon/hint/show-hint.css)">
   <link rel="stylesheet" href="https://cdn.jsdelivr.net/jquery.ui/1.11.4/jquery-ui.min.css">
-  <link rel="stylesheet" href="https://cdn.jsdelivr.net/codemirror/4.5.0/theme/eclipse.css">
   <style>
     .CodeMirror {
       border: 1px solid #eee;