Add cssclass for footer-nav and improve button-style in footer

src/pretix/presale/templates/pretixpresale/base.html

@@ -80,7 +80,7 @@
                 <li>{{ footer_text }}</li>
             {% endif %}
             {% for f in footer %}
-                <li><a href="{% safelink f.url %}" target="_blank" rel="noopener">{{ f.label }}</a></li>
+                <li><a class="{{ f.cssclass }}" href="{% safelink f.url %}" target="_blank" rel="noopener">{{ f.label }}</a></li>
             {% endfor %}
             {% include "pretixpresale/base_footer.html" %} {# removing or hiding this might be in violation of pretix' license #}
             </ul>

src/pretix/static/pretixpresale/scss/main.scss

@@ -201,13 +201,16 @@ footer nav li:not(:first-child):before {
     width: 1.5em;
     text-align: center;
 }
+footer nav .btn, 
 footer nav .btn-link {
     display: inline;
-    padding: 0;
     margin: 0;
     font-size: 11px;
     vertical-align: baseline;
 }
+footer nav .btn-link {
+    padding: 0;
+}
 
 .js-only {
     display: none;