Only set up REST server if it's actually enabled in the config file

[mountaindude]

What version of Butler are you using?

9.0.0

What version of Node.js are you using? Not applicable if you use the standalone version of Butler.

18.4

What command did you use to start Butler?

node butler.js

What operating system are you using?

macOS

What CPU architecture are you using?

x86_64

What Qlik Sense versions are you using?

na

Describe the Bug

REST server is always configured and initialised, even if it's disabled in the config file.

Expected Behavior

Respect settings in the config file.

To Reproduce

No response