Merge branch '1.10.x' of ssh://github.com/chamilo/chamilo-lms into 1.10.x

main/inc/lib/usermanager.lib.php

@@ -2751,7 +2751,8 @@ class UserManager
                 if ($session_visibility == SESSION_INVISIBLE) {
                     continue;
                 }
-
+                // This query is horribly slow when more than a few thousand
+                // users and just a few sessions to which they are subscribed
                 $id_session = $enreg['id'];
                 $personal_course_list_sql = "SELECT DISTINCT
                         course.code code,

main/social/groups.php

@@ -10,7 +10,7 @@ $cidReset = true;
 require_once '../inc/global.inc.php';
 
 api_block_anonymous_users();
-if (api_get_setting('allow_social_tool') != 'true') {
+if (api_get_setting('allow_social_tool') != 'true' && !api_is_platform_admin()) {
     api_not_allowed();
 }