Correct missing fields in database schema

[netandreus]

This pull request solves bugs such this, appears after sync is started.

[10-Mar-20 12:05:57] NOTICE: SQLSTATE[42S22]: Column not found: 1054 Unknown column 'uid_validity' in 'field list'
[10-Mar-20 12:05:57] CRITICAL: System encountered an un-recoverable database error. Going to halt now, please see the log file for info.
#0 /var/www/libremail/sync/sync(222): App\Diagnostics::checkDatabaseException(Object(Pimple\Container), Object(PDOException), true, true)
#1 {main}