Rootstock: include $DOMAIN in http hosts whitelist

rskj's hosts whitelist is exact-match (no wildcards). Use HOCON env-var
substitution ${?DOMAIN} to inject the per-host public domain into the
allowed list. Pass DOMAIN env var into the container via the rskj
template.

Allowed hosts list: [localhost, 127.0.0.1, ::1, ${?DOMAIN}]
- localhost variants for direct/internal access
- DOMAIN for traefik-forwarded requests (Host header = public domain)

rootstock/rskj/rootstock-bamboo-rskj-archive.yml

@@ -52,6 +52,7 @@ services:
       - 8545
       - 8546
     environment:
+      DOMAIN: ${DOMAIN}
       RSKJ_SYS_PROPS: -Drpc.providers.web.http.bind_address=0.0.0.0
     restart: unless-stopped
     stop_grace_period: 5m