Moving UPDATE defines/constants out of boot

boot.php

@@ -43,13 +43,6 @@ define('FRIENDICA_VERSION',      '2018.12-dev');
 define('DFRN_PROTOCOL_VERSION',  '2.23');
 define('NEW_UPDATE_ROUTINE_VERSION', 1170);
 
-/**
- * @brief Constants for the database update check
- */
-const DB_UPDATE_NOT_CHECKED = 0; // Database check wasn't executed before
-const DB_UPDATE_SUCCESSFUL = 1;  // Database check was successful
-const DB_UPDATE_FAILED = 2;      // Database check failed
-
 /**
  * @brief Constant with a HTML line break.
  *
@@ -119,18 +112,6 @@ define('REGISTER_OPEN',          2);
  * @}
 */
 
-/**
- * @name Update
- *
- * DB update return values
- * @{
- */
-define('UPDATE_SUCCESS', 0);
-define('UPDATE_FAILED',  1);
-/**
- * @}
- */
-
 /**
  * @name CP
  *