fix(Dockerfile): remove bogus -bind-addr, and use default -addr

Dockerfile

@@ -7,4 +7,4 @@ RUN apt-get install -y golang
 ADD . /opt/etcd
 RUN cd /opt/etcd && ./build
 EXPOSE 4001 7001
-ENTRYPOINT ["/opt/etcd/etcd", "-addr", "0.0.0.0:4001", "-bind-addr", "0.0.0.0:7001"]
+ENTRYPOINT ["/opt/etcd/etcd"]