Internal: Update version to 1.11.18 stable

Author: ywarnier

main/install/version.php

@@ -14,7 +14,7 @@
  * Variables used from the main/install/index.php.
  */
 $new_version = '1.11.18';
-$new_version_status = 'dev';
+$new_version_status = 'stable';
 $new_version_last_id = 0;
 $new_version_stable = true;
 $new_version_major = false;