[swift5][client] fix binary response

[4brunu]

This PR fixes the download of binary response and is related to #9308

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@jgavris (2017/07) @ehyche (2017/08) @Edubits (2017/09) @jaz-ah (2017/09) @4brunu (2019/11)

[aymanbagabas]

I hope this would be the default behavior in 5.2.x cause if not, #9583 would break since it doesn't handle file/binary <-> URL relations.

[4brunu]

@aymanbagabas I left some comments on #9308 (comment) related to this