Fix routes reference when using CORS settings

During a JSHint cleanup:

https://github.com/node-red/node-red/commit/4770a06679b997575a0baea89aea6ec6c45b3060#diff-53e5d380639e123b98b5a5286f85104e

it looks like a bug was introduced.  When the reference to 'routes' as changed to 'route' in an entire block of code but one of them causes an error to occur (TypeError: Cannot read property 'length' of undefined) when httpNodeCors is set.