bugfix NoReverseMatch if category is not translated

djangocms_blog/templates/djangocms_blog/includes/blog_item.html

@@ -18,7 +18,9 @@
             <ul class="post-detail tags">
                 {% if post.categories.exists %}
                     {% for category in post.categories.all %}
+                        {% if category.slug %}
                             <li class="category_{{ forloop.counter }}"><a href="{% url 'djangocms_blog:posts-category' category=category.slug %}" class="blog-categories-{{ category.count }}">{{ category.name }}</a>{% if not forloop.last %}, {% endif %}</li>
+                        {% endif %}
                     {% endfor %}
 			    {% endif %}
                 {% if post.tags.exists %}