Replace deprecated variables .Hugo and .UniqueID with hugo and .File.UniqueID.

layouts/partials/mobilemenu.html

@@ -1,3 +1,7 @@
+{{ $home := relLangURL "/" -}}
+{{ $currentSection := .Section -}}
+{{ $currentID := "" -}}
+{{ with .File }}{{ $currentID = .UniqueID }}{{ end -}}
 <div class="mobile-nav" dir="ltr">
   <div class="mobile-nav__cover"></div>
   <a href="#navigation" class="mobile-nav__toggle" aria-haspopup="true" role="button">{{ i18n "menu_mobile" }}</a>
@@ -6,16 +10,13 @@
     {{ if .Site.IsMultiLingual }}{{ partial "language-selector.html" . }}{{ end }}
     {{ if $.Param "search" }}{{ partialCached "search.html" . }}{{ end }}
     </div>
-    {{ $home := relLangURL "/" }}
-    {{ $currentSection := .Section }}
-    {{ $currentID := .UniqueID }}
     <nav class="mobile-nav__main-menu">
     <h2 class="visually-hidden">{{ i18n "menu_title" }}</h2>
     <ul class="mobile-nav__navbar">
     <li><a class="{{ if .IsHome }}active{{ end }}" href="{{ $home }}">{{ i18n "menu_home" }}</a></li>
     {{ range where .Site.Pages "Section" "" -}}
     {{ if ne .RelPermalink (string $home) -}}
-    <li><a class="{{ if eq $currentID .UniqueID }}active{{ end }}" href="{{ .RelPermalink }}">{{ .Title }}</a></li>
+    <li><a class="{{ if eq $currentID .File.UniqueID }}active{{ end }}" href="{{ .RelPermalink }}">{{ .Title }}</a></li>
     {{ end -}}
     {{ end -}}
     {{ range $.Site.Home.Sections -}}