return always null for user.is_admin; closes #546

Author: following5

okapi/services/users/user/docs.xml

@@ -28,11 +28,8 @@
             <li><b>profile_url</b> - URL of the user's Opencaching profile page,</li>
             <li class='deprecated'>
                 <p><b>is_admin</b> - deprecated
-                (<a href='https://github.com/opencaching/okapi/issues/410'>why?</a>).
-                boolean, true is user has admin privileges.</p>
-                <p>This value can be accessed only with <b>Level 3</b> Authentication
-                and only for the user of your Access Token. For all other reads, is_admin
-                will equal <b>null</b>.</p>
+                (<a href='https://github.com/opencaching/okapi/issues/410'>why?</a>),
+                always <b>null</b>.</p>
             </li>
             <li>
                 <b>internal_id</b> - internal ID of the user (<b>DO NOT</b> use this!

okapi/services/users/users/WebService.php

@@ -59,15 +59,7 @@ public static function call(OkapiRequest $request)
                     case 'uuid': $entry['uuid'] = $row['uuid']; break;
                     case 'username': $entry['username'] = $row['username']; break;
                     case 'profile_url': $entry['profile_url'] = Settings::get('SITE_URL')."viewprofile.php?userid=".$row['user_id']; break;
-                    case 'is_admin':
-                        if (!$request->token) {
-                            $entry['is_admin'] = null;
-                        } elseif ($request->token->user_id != $row['user_id']) {
-                            $entry['is_admin'] = null;
-                        } else {
-                            $entry['is_admin'] = $row['admin'] ? true : false;
-                        }
-                        break;
+                    case 'is_admin': $entry['is_admin'] = null; break;
                     case 'internal_id': $entry['internal_id'] = $row['user_id']; break;
                     case 'date_registered':
                         $entry['date_registered'] = date("Y-m-d", strtotime($row['date_created']));