bouncer: Error when no signature header sent

[brettski]

When no signature header the application errors due to sending response headers a second time. Check error path and error path responses.

errorHandler unknown error: Cannot set headers after they are sent to the client
Sentry Logger [log]: SDK not enabled, will not capture event.
Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
    at new NodeError (node:internal/errors:372:5)
    at ServerResponse.setHeader (node:_http_outgoing:576:11)
    at ServerResponse.header (/Users/brettski/tc/that-api-functions/functions/bouncer/node_modules/express/lib/response.js:794:10)
    at ServerResponse.send (/Users/brettski/tc/that-api-functions/functions/bouncer/node_modules/express/lib/response.js:174:12)
    at ServerResponse.json (/Users/brettski/tc/that-api-functions/functions/bouncer/node_modules/express/lib/response.js:278:15)
    at errorHandler (/Users/brettski/tc/that-api-functions/functions/bouncer/__build__/middleware/errorHandler.js:15:28)
    at Layer.handle_error (/Users/brettski/tc/that-api-functions/functions/bouncer/node_modules/express/lib/router/layer.js:71:5)
    at trim_prefix (/Users/brettski/tc/that-api-functions/functions/bouncer/node_modules/express/lib/router/index.js:326:13)
    at /Users/brettski/tc/that-api-functions/functions/bouncer/node_modules/express/lib/router/index.js:286:9
    at Function.process_params (/Users/brettski/tc/that-api-functions/functions/bouncer/node_modules/express/lib/router/index.js:346:12)