Adds entry to pending change log.
Adds entry to pending change log.

Adds PR #2557 to pending change log.
yxd-hde/aws-sdk-go,jasdel/aws-sdk-go,yxd-hde/aws-sdk-go,yxd-hde/aws-sdk-go,yxd-hde/aws-sdk-go,aws/aws-sdk-go