Update to AWS KMS manual page

On this page:

https://mariadb.com/kb/en/mariadb-enterprise/mariadb-enterprise-aws-kms-encryption-plugin-setup-guide/

Under the "Installation" section, it says to simply run the following to install:

"To install, the AWS KMS plugin, set up the MariaDB Enterprise Repository for MariaDB Enterprise 10.1 and then execute yum install MariaDB-aws-key-management or apt install mariadb-aws-key-management-10.1."

However, this fails with the following if your aws-key-management-region is not "us-east-1":

2016-11-30 18:09:01 139899400259840 [ERROR] AWS KMS plugin : GenerateDataKeyWithoutPlaintext failed : NotFoundException - Alias arn:aws:kms:us-east-1:744686699669:alias/mariadb_test is not found.

In which case, you must set aws-key-management-region to the proper region in your server.cnf file for this to install, for instance:

aws-key-management-region = us-west-2

I'd like to ask if we can please add something to this effect on that manual page under the "Installation" section.

Thank you for your consideration.