Настроить на DEV нормальную работу курсов

apps/course/templates/course/_items.html

@@ -8,7 +8,7 @@
     {% if course.is_deferred_start and course.status == 2 %}data-future-course data-future-course-time={{ course.deferred_start_at.timestamp }}{% endif %}
 >
 <a class="courses__preview" href="{% if course.status <= 1 %}{% url 'course_edit' course.id %}{% else %}{{ course.url }}{% endif %}">
-  {% if course.cover %}
+  {% if course.cover and course.cover.image_thumbnail %}
   <img class="courses__pic" src="{{ course.cover.image_thumbnail.url }}" width="{{ course.cover.image_thumbnail.width }}" />
   {% else %}
   <img class="courses__pic" src="{% static 'img/no_cover.png' %}" width="300px" />

apps/course/templates/course/course.html

@@ -212,7 +212,7 @@
         {% endif %}
       </div>
       <a class="course__video video" href="#">
-        {% if course.cover %}
+        {% if course.cover and course.cover.image %}
         <img class="video__pic" src="{{ course.cover.image.url }}"/>
         {% else %}
 
@@ -272,7 +272,7 @@
 {% endif %}
 <div
   class="course course_promo"
-  style="background-image: url({% if course.cover %}{{ course.cover.image.url }}{% else %}{% static 'img/no_cover.png' %}{% endif %});"
+  style="background-image: url({% if course.cover and course.cover.image %}{{ course.cover.image.url }}{% else %}{% static 'img/no_cover.png' %}{% endif %});"
   >
   <div class="course__center center center_sm">
     <div class="course__head">