[swift5] URLSession: Fix memory leak of SessionDelegate

[fl034]

cleanupRequest() is only called on error for now. So sessionDelegate doesn't get deallocated after request.

I think it's okay to call cleanupRequest() directly after the processing of the response, instead of putting it in the completion closure, since it will only deallocate when not in use anymore. What do you guys think?

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[fl034]

@4brunu

[4brunu]

Looks good to me.
Thanks for your contribution.

[4brunu]

Interesting, I didn't know this API.
Can you please comment on the need of this?
Just curious.
Thanks 😊

[fl034]

This invalidates the session after the all tasks of this session have completely finished. New tasks cannot be started on this session.
This call is not necessary, but good practice, since we're creating a session for each request, so after a task as finished we don't need the session anymore.

[4brunu]

Nice, thanks 👍

[4brunu]

For me it's ready to merge 👍