Specifying a port in jco serve errors

[rajsite]

Running jco serve with a custom port, i.e. jco serve --port 8010 build/example_s.wasm

Fails with error:

 jco serve --port "8010" --jco-dir build-jco build/example_s.wasm

file:///home/rajsite/dev/mraj-sle-api-proxy/example-app/build-jco/_run.js:12
    console.error(`Server listening on ${port}...`);
                                         ^

ReferenceError: port is not defined
    at file:///home/rajsite/dev/mraj-sle-api-proxy/example-app/build-jco/_run.js:12:42

Looks like the serve script accidentally escapes the port in the template string so it is emitted as a variable reference instead of replaced:

jco/src/cmd/run.js

Line 56 in a93ecb9

console.error(\`Server listening on \${port}...\`);