update aws-sdk to fix issue with encrypted blobs

AWS upgraded OpenSSL and introduced a regression for aws-sdk blobs using
encryption.

"These issues have existed in the code for some time, but negative effects
were only recently realized when a change in OpenSSL behavior resulted in
empty packets being sent over the wire - yielding these caused exceptions
downstream, rather than waiting for the content to be sent. That issue should
no longer occur"

See https://github.com/aws/aws-sdk-ruby/issues/557#issuecomment-45390398 for
upstream bug and fix.

https://github.com/aws/aws-sdk-ruby/commit/0898b0cbfb5ab883249c286bbdcd47359da83f9e
is the patch we need. This patch is applied to v1.44.0.

Thanks @frodenas for bug hunting with me.