Better button styling

[CI skip]
Signed-off-by: Michal Čihař <michal@cihar.com>

weblate/html/about.html

@@ -43,7 +43,7 @@
   </p>
 </div>
   <div class="panel-footer">
-  <a class="btn btn-default" href="https://weblate.org/hosting/">{% trans "View hosting plans" %}</a>
+  <a class="btn btn-primary" href="https://weblate.org/hosting/">{% trans "View hosting plans" %}</a>
   <a class="btn btn-default" href="{% url 'contact' %}?subject=Commercial hosting">{% trans "Contact us for commercial hosting" %}</a>
   </div>
 </div>