Fix Docker entrypoint

[bretthoerner]

While trying to debug capture I noticed this is incorrect, the $ENTRYPOINT isn't being expanded:

        "Args": [
            "-c",
            "[ $ENTRYPOINT ]",
            "--",
            "/usr/local/bin/capture-server"
        ],

Annoying docker magic... apparently the version in the diff will expand $BIN.

Hooks are working because we override command: in the deployment.