Fix a stupid error in the scheduled task for recounting mentions

Signed-off-by: emanuele <emanuele45@gmail.com>

sources/subs/ScheduledTask.class.php

@@ -1529,7 +1529,7 @@ public function user_access_mentions()
 				$user_see_board = memberQuerySeeBoard($row['id_member']);
 
 				// Find out if this user cannot see something that was supposed to be able to see
-				$request = $db->query('', '
+				$request2 = $db->query('', '
 					SELECT mnt.id_mention
 					FROM {db_prefix}log_mentions as mnt
 						LEFT JOIN {db_prefix}messages AS m ON (m.id_msg = mnt.id_msg)
@@ -1546,7 +1546,7 @@ public function user_access_mentions()
 					)
 				);
 				// One row of results is enough: scheduleTaskImmediate!
-				if ($db->num_rows($request) == 1)
+				if ($db->num_rows($request2) == 1)
 				{
 					if (!empty($modSettings['user_access_mentions']))
 						$modSettings['user_access_mentions'] = @unserialize($modSettings['user_access_mentions']);