Revert "MDL-43852 Filters Fixed naked-OR conditions."

While the patch worked as intended, we discovered some other concerns
about use of this setting in testing.

This reverts commit 840c1c5.

course/format/renderer.php

@@ -585,7 +585,7 @@ protected function section_nav_selection($course, $sections, $displaysection) {
         $section = 1;
         while ($section <= $course->numsections) {
             $thissection = $modinfo->get_section_info($section);
-            $showsection = ($thissection->uservisible or !$course->hiddensections);
+            $showsection = $thissection->uservisible or !$course->hiddensections;
             if (($showsection) && ($section != $displaysection) && ($url = course_get_url($course, $section))) {
                 $sectionmenu[$url->out(false)] = get_section_name($course, $section);
             }

filter/mediaplugin/filter.php

@@ -66,7 +66,7 @@ public function filter($text, array $options = array()) {
         }
 
         // Check SWF permissions.
-        $this->trusted = (!empty($options['noclean']) or !empty($CFG->allowobjectembed));
+        $this->trusted = !empty($options['noclean']) or !empty($CFG->allowobjectembed);
 
         // Handle all links that contain any 'embeddable' marker text (it could
         // do all links, but the embeddable markers thing should make it faster