Fix batch_send_failures.

In aws-sdk (v1.32.0) the number of args for `batch_send_failures` is now 3 (instead of 2).  We had patched this method with our own version, and `Queue#batch_send` is now raising an error as a result of this.

It turns out that the reason for patching `batch_send_failures` has now been integrated into the aws-sdk.

https://github.com/aws/aws-sdk-ruby/blob/v1.32.0/lib/aws/sqs/queue.rb#L685-L711

This removes the patch to `batch_send_failures` and updates the aws-sdk to v1.32.0.