Due to internals of pistache, a write after a retry may be with a
different address than the original call. By default, OpenSSL doesn't
like that:

    SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER

        Make it possible to retry SSL_write() with changed buffer location
        (the buffer contents must stay the same). This is not the default to
        avoid the misconception that non-blocking SSL_write() behaves like
        non-blocking write().

This should fix any weird behavior on large file / responses (#807)
Signed-off-by: Louis Solofrizzo <lsolofrizzo@scaleway.com>