geth: respect HOST_IP env; remove override that broke --nat=extip

[radik878]

The entrypoint hard-set HOST_IP="" which overwrote any environment-provided value. As a result, the conditional that appends --nat=extip:$HOST_IP never executed, making it impossible to advertise a public IP even when HOST_IP was supplied via env. This fixes the issue by removing the overriding assignment and adding a clarifying comment to set HOST_IP via environment. Now, when HOST_IP is non-empty, --nat=extip is correctly applied; when unset/empty, it’s omitted.

[cb-heimdall]

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[github-actions[bot]]

This pull request was closed because it has been inactive for 5 days since being marked as stale.