SQS MessageBody size validation is incorrect

[fredshonorio]

If I'm reading the code correctly, MessageBody expects a string up to 256 characters in length, this is incorrect according to the documentation, it's 256kb not bytes.

Additionally, the minimum is 1, not 0, and measuring by character length is certain to cause issues when non-ascii characters are in the message.

I could PR a fix if you'd like.

[fredshonorio]

I guess measuring by byte size is not really important because the queue can be configured for smaller sizes anyway (the maximum size is queue dependent).

[amrhassan]

Thank you for reporting. I guess validating against the maximum size wouldn't hurt.

I'll publish a fix in a few minutes..