Follow-up to 03366b61d. Since there are no more const members in the
PGoauthBearerRequest struct, the previous memcpy() can be replaced with
simple assignment.
Author: Jacob Champion <[email protected]>
Discussion: https://postgr.es/m/p4bd7mn6dxr2zdak74abocyltpfdxif4pxqzixqpxpetjwt34h%40qc6jgfmoddvq