fix(i18n): prevent double /de/ in navigation

Author: mroehl86

_includes/layouts/base.njk

@@ -128,7 +128,7 @@
     </label>
     <input type="checkbox" id="menu-button" aria-hidden="true" />
     <ul class="menu">
-      {% set homeLink = (locale == "de" ? "/de/" : "/") | url %}
+      {% set homeLink = "/de/" if locale == "de" else "/" %}
       {% set newsLink = "/blog/" | url %}
       {% set servicesLink = "/services/" | url %}
       {% set partnersLink = "/partners/" | url %}
@@ -156,7 +156,8 @@
           <div class="line"></div>
         </a>
         {% else %}
-        <a href="{{ ('/de' + page.url) | url }}" title="Wechsle Sprache zu Deutsch">
+        {% set deUrl = page.url if page.url.startsWith('/de/') else '/de' + page.url %}
+        <a href="{{ deUrl }}" title="Wechsle Sprache zu Deutsch">
           EN<br><span class="font-weight-light">DE</span>
           <div class="line"></div>
         </a>