category fix

apps/course/templates/course/_items.html

@@ -48,7 +48,7 @@
 </a>
 <div class="courses__details">
     <a class="courses__theme theme {{ theme_color }}"
-       href="{% url 'courses' %}?category={{ course.category.title }}">{{ course.category | upper }}</a>
+       href="{% url 'courses' %}?category={{ course.category.id }}">{{ course.category | upper }}</a>
     {% if not course.is_free %}
       <div class="courses__price">{{ course.price|floatformat:"-2" }}₽</div>
     {% endif %}