Bug#864684: awscli fails with Regions that only support Signature Version 4

[Chris Bainbridge]

Package: awscli
Version: 1.4.2-1
Severity: important

awscli works on older AWS regions but fails on newer regions that require
version 4 signatures:

$ /usr/bin/aws --region eu-west-2 ec2 describe-instances

A client error (AuthFailure) occurred when calling the DescribeInstances
operation: AWS was not able to validate the provided access credentials

$ /usr/bin/aws --region eu-west-1 ec2 describe-instances
{
    "Reservations": []
}

Relevant: https://forums.aws.amazon.com/message.jspa?messageID=578908