aws_key_management shouldn't generate user warnings

MariaDB [test]> create table test.t1(a int) encryption_key_id=2;

Query OK, 0 rows affected, 2 warnings (1.44 sec)

MariaDB [test]> show warnings;

+-------+------+---------------------------------------------------------------------+

| Level | Code | Message                                                             |

+-------+------+---------------------------------------------------------------------+

| Note  | 1105 | AWS KMS plugin: generated encrypted datakey for key id=2, version=1 |

| Note  | 1105 | AWS KMS plugin: loaded key 2, version 1, key length 128 bit         |

+-------+------+---------------------------------------------------------------------+

2 rows in set (0.00 sec)

MariaDB [(none)]> select * from test.t1;

Empty set, 1 warning (0.28 sec)

MariaDB [(none)]> show warnings;

+-------+------+-------------------------------------------------------------+

| Level | Code | Message                                                     |

+-------+------+-------------------------------------------------------------+

| Note  | 1105 | AWS KMS plugin: loaded key 2, version 1, key length 128 bit |

+-------+------+-------------------------------------------------------------+

1 row in set (0.00 sec