fix issue where URLs with special characters would not work in search

Author: Erik2609

layouts/partials/head.html

@@ -19,7 +19,7 @@
 
 <meta name="search_title" content="{{if .Params.search.title}}{{.Params.search.title}}{{else}}{{.Params.title}}{{end}}"> 
 <meta name="search_subtitle" content="{{if .Params.search.title}}{{.Params.search.subtitle}}{{else}}{{.Params.subtitle}}{{end}}"> 
-<meta name="search_image" content="{{if .Params.search.image}}{{.Params.search.image}}{{else}}{{.Params.image}}{{end}}"> 
+<meta name="search_image" content="{{if .Params.search.image}}{{.Params.search.image | relURL}}{{else}}{{.Params.image | relURL}}{{end}}"> 
 
 <!--Favicon-->
 <link rel="shortcut icon" href="{{ site.Params.favicon | absURL }}" type="image/x-icon">