Handle 'ThrottledException' error code to automatically retry requests.
Handle 'ThrottledException' error code to automatically retry requests.

Throttling exception error-codes are inconsistent across aws services. This
commit handles another variation of the throttling error thrown by some of
the services.

cedral/aws-sdk-cpp,jt70471/aws-sdk-cpp,svagionitis/aws-sdk-cpp,aws/aws-sdk-cpp,awslabs/aws-sdk-cpp,cedral/aws-sdk-cpp,jt70471/aws-sdk-cpp,svagionitis/aws-sdk-cpp,cedral/aws-sdk-cpp,jt70471/aws-sdk-cpp,JoyIfBam5/aws-sdk-cpp,cedral/aws-sdk-cpp,JoyIfBam5/aws-sdk-cpp,cedral/aws-sdk-cpp,awslabs/aws-sdk-cpp,aws/aws-sdk-cpp,jt70471/aws-sdk-cpp,svagionitis/aws-sdk-cpp,cedral/aws-sdk-cpp,jt70471/aws-sdk-cpp,aws/aws-sdk-cpp,svagionitis/aws-sdk-cpp,aws/aws-sdk-cpp,awslabs/aws-sdk-cpp,awslabs/aws-sdk-cpp,JoyIfBam5/aws-sdk-cpp,JoyIfBam5/aws-sdk-cpp,svagionitis/aws-sdk-cpp,svagionitis/aws-sdk-cpp,jt70471/aws-sdk-cpp,aws/aws-sdk-cpp,aws/aws-sdk-cpp,JoyIfBam5/aws-sdk-cpp,JoyIfBam5/aws-sdk-cpp