Fixed build rust doc
BUILD.md included a command with an invalid environment variable,
which prevented the proxy from starting.
The IP address `0` is no longer considered valid by the proxy, so the
doc now refers to `0.0.0.0` instead.
@@ -324,7 +324,7 @@ To build and run the Rust proxy:
```bash
cargo build -p conduit-proxy
CONDUIT_PROXY_LOG=trace \
- CONDUIT_PROXY_PUBLIC_LISTENER=tcp://0:5432 \
+ CONDUIT_PROXY_PUBLIC_LISTENER=tcp://0.0.0.0:5432 \
CONDUIT_PROXY_PRIVATE_FORWARD=tcp://127.0.0.1:1234 \
CONDUIT_PROXY_CONTROL_URL=tcp://127.0.0.1:8086 \
target/debug/conduit-proxy
