Fix link for CloudFormation helper scripts

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/cfn-helper-scripts-reference.html

Signed-off-by: Luca Carrogu <[email protected]>

Author: lukeseawalker

amis/packer_centos6.json

@@ -239,7 +239,7 @@
       "type" : "shell",
       "inline" : [
         "region=\"{{user `region`}}\"",
-        "bucket=\"s3.${region}.amazonaws.com\"",
+        "bucket=\"s3.amazonaws.com\"",
         "[[ ${region} =~ ^cn- ]] && bucket=\"s3.cn-north-1.amazonaws.com.cn\"",
         "curl --retry 3 -L -o /tmp/aws-cfn-bootstrap-latest.tar.gz https://${bucket}/cloudformation-examples/aws-cfn-bootstrap-latest.tar.gz",
         "sudo pip install /tmp/aws-cfn-bootstrap-latest.tar.gz"

amis/packer_centos7.json

@@ -236,7 +236,7 @@
       "type" : "shell",
       "inline" : [
         "region=\"{{user `region`}}\"",
-        "bucket=\"s3.${region}.amazonaws.com\"",
+        "bucket=\"s3.amazonaws.com\"",
         "[[ ${region} =~ ^cn- ]] && bucket=\"s3.cn-north-1.amazonaws.com.cn\"",
         "curl --retry 3 -L -o /tmp/aws-cfn-bootstrap-latest.tar.gz https://${bucket}/cloudformation-examples/aws-cfn-bootstrap-latest.tar.gz",
         "which pip2",

amis/packer_ubuntu1404.json

@@ -245,7 +245,7 @@
       "inline_shebang" : "/bin/bash -e",
       "inline" : [
         "region=\"{{user `region`}}\"",
-        "bucket=\"s3.${region}.amazonaws.com\"",
+        "bucket=\"s3.amazonaws.com\"",
         "[[ ${region} =~ ^cn- ]] && bucket=\"s3.cn-north-1.amazonaws.com.cn\"",
         "curl --retry 3 -L -o /tmp/aws-cfn-bootstrap-latest.tar.gz https://${bucket}/cloudformation-examples/aws-cfn-bootstrap-latest.tar.gz",
         "sudo pip install /tmp/aws-cfn-bootstrap-latest.tar.gz"

amis/packer_ubuntu1604.json

@@ -248,7 +248,7 @@
       "inline_shebang" : "/bin/bash -e",
       "inline" : [
         "region=\"{{user `region`}}\"",
-        "bucket=\"s3.${region}.amazonaws.com\"",
+        "bucket=\"s3.amazonaws.com\"",
         "[[ ${region} =~ ^cn- ]] && bucket=\"s3.cn-north-1.amazonaws.com.cn\"",
         "curl --retry 3 -L -o /tmp/aws-cfn-bootstrap-latest.tar.gz https://${bucket}/cloudformation-examples/aws-cfn-bootstrap-latest.tar.gz",
         "sudo pip install /tmp/aws-cfn-bootstrap-latest.tar.gz"