remove

`<script src="{{"js/html5shiv-printshiv.min.js" | relURL}}{{ if not .Site.Params.disableAssetsBusting }}?{{ now.Unix }}{{ end }}"></script>`
This was only ever needed for IE8 (which is not supported with this theme since it uses a newer version of jQuery). Furthermore it should be loaded in the head anyway. IE9 supports HTML5 tags and does not need this polyfill at all.

layouts/partials/footer.html

@@ -61,7 +61,6 @@
     <script src="{{"js/perfect-scrollbar.jquery.min.js" | relURL}}{{ if not .Site.Params.disableAssetsBusting }}?{{ now.Unix }}{{ end }}"></script>
     <script src="{{"js/jquery.sticky.js" | relURL}}{{ if not .Site.Params.disableAssetsBusting }}?{{ now.Unix }}{{ end }}"></script>
     <script src="{{"js/featherlight.min.js" | relURL}}{{ if not .Site.Params.disableAssetsBusting }}?{{ now.Unix }}{{ end }}"></script>
-    <script src="{{"js/html5shiv-printshiv.min.js" | relURL}}{{ if not .Site.Params.disableAssetsBusting }}?{{ now.Unix }}{{ end }}"></script>
     <script src="{{"js/highlight.pack.js" | relURL}}{{ if not .Site.Params.disableAssetsBusting }}?{{ now.Unix }}{{ end }}"></script>
     <script>hljs.initHighlightingOnLoad();</script>
     <script src="{{"js/modernizr.custom-3.6.0.js" | relURL}}{{ if not .Site.Params.disableAssetsBusting }}?{{ now.Unix }}{{ end }}"></script>