fix: disappearing filters on changelist (#999) (#1042)

Author: sezginacer

src/unfold/templates/admin/search_form.html

@@ -11,8 +11,10 @@
                 </button>
             </div>
 
-            {% for pair in cl.params.items %}
-                {% if pair.0 != search_var %}<input type="hidden" name="{{ pair.0 }}" value="{{ pair.1 }}">{% endif %}
+            {% for pair in cl.filter_params.items %}
+                {% for val in pair.1 %}
+                    {% if pair.0 != search_var %}<input type="hidden" name="{{ pair.0 }}" value="{{ val }}">{% endif %}
+                {% endfor %}
             {% endfor %}
         </form>
     </div>