fae75306ba scripted-diff: Set gitian arch back to amd64 (MarcoFalke)
Pull request description:
This was required to allow gitian builds on non-amd64 architecture, however, it seems to break the current builds (with lxc), see https://github.com/bitcoin/bitcoin/pull/17409#issuecomment-554099626
Also, the gititan builds wouldn't be deterministic across arches anyway, see #17468
So instead of wasting more time on this, revert the change and hope that guix allows to compile on non-amd64 architectures.
Top commit has no ACKs.
Tree-SHA512: 801e9a30ae1b0882ef45d5eb3a3cf80f3ace3b99db046069dbd95b6162119e977e3cf3134287d1ac5d09483906206acc71e1ac34d6b74dbc533d46aaf73f5cc2