Increase Payment proxy timeouts
This is a stopgap measure to make the nginx in front of zkapissuer not time out anymore.
Meejah ran into trouble with this happening on staging:
zkapissuer logs:
Dec 10 04:43:15 payments zkapissuer-start[134340]: POST /v1/redeem
Dec 10 04:43:15 payments zkapissuer-start[134340]: Accept:
Dec 10 04:43:15 payments zkapissuer-start[134340]: Status: 400 Bad Request 601.417276158s
NGINX logs:
[error] 155498#155498: *49226 upstream timed out (110: Connection timed out) while reading response header from upstream, client:
24.114.39.194, server: payments.privatestorage-staging.com, request: "POST /v1/redeem HTTP/1.1", upstream: "http://127.0.0.1:1061/v1/redeem", host: "payments.privatestorage-staging.com"