MDL-43504 Course: Include the course/category collapse JS correctly

This was previously only included when there were hidden categories to show
which were not yet visible. As a result, if all categories were visible,
then the JS was not included.

course/renderer.php

@@ -1463,8 +1463,6 @@ protected function coursecat_category(coursecat_helper $chelper, $coursecat, $de
                 $classes[] = 'with_children';
                 $classes[] = 'collapsed';
             }
-            // Make sure JS file to expand category content is included.
-            $this->coursecat_include_js();
         } else {
             // load category content
             $categorycontent = $this->coursecat_category_content($chelper, $coursecat, $depth);
@@ -1474,6 +1472,10 @@ protected function coursecat_category(coursecat_helper $chelper, $coursecat, $de
                 $classes[] = 'expanded';
             }
         }
+
+        // Make sure JS file to expand category content is included.
+        $this->coursecat_include_js();
+
         $content = html_writer::start_tag('div', array(
             'class' => join(' ', $classes),
             'data-categoryid' => $coursecat->id,