fix: added query to check if alt pages really exist

templates/header_slim.html

@@ -10,13 +10,13 @@
         </div>
         <nav class="header__secondary_nav">
             <ul class="secondary_nav__navlist">
-            {% for alt in get_alts(this) %}
+                {% for alt in get_alts(this) %}
-              {%- if this.alt != alt %}
+                  {%- if this.alt != alt and site.get('.'|url(alt=alt)) %}
-                <li class="secondary_nav__navitem">
+                    <li class="secondary_nav__navitem">
-                    <a class="secondary_nav__navlink" href="{{ '.'|url(alt=alt) }}">{{ alt|title|upper }}</a>
+                        <a class="secondary_nav__navlink" href="{{ '.'|url(alt=alt) }}">{{ alt|title|upper }}</a>
-                </li>
+                    </li>
-              {% endif -%}
+                  {% endif -%}
-              {% endfor %}
+                {% endfor %}
                 <li class="secondary_nav__navitem">
                     <a class="secondary_nav__navlink" href="https://forum.wtf-eg.de/">Login</a>
                 </li>