Solution :
Your s3cmd has older version, you need to upgrade it. Download latest one and use the file everywhere.
https://sourceforge.net/projects/s3tools/files/s3cmd/1.6.1/
I faced this problem on 1.1 version of s3cmd, I downloaded latest and got 1.6. After that I did not get the error.
How to use the downloaded folder.
1) Extract the folder and open it.
2) Now run your s3cmd command using this downloaded folder.
Your s3cmd has older version, you need to upgrade it. Download latest one and use the file everywhere.
https://sourceforge.net/projects/s3tools/files/s3cmd/1.6.1/
I faced this problem on 1.1 version of s3cmd, I downloaded latest and got 1.6. After that I did not get the error.
How to use the downloaded folder.
1) Extract the folder and open it.
2) Now run your s3cmd command using this downloaded folder.
/home/ubuntu/s3cmd-1.6.1/s3cmd ls s3:// /home/ubuntu/s3cmd-1.6.1/s3cmd -c /home/ubuntu/.s3cfg put /tmp/file.sql s3://bucketname