Navigating to a definition in a jar file throws error in console

[bpringe]

Repro:

0. Jack-in
1. Open a file, Go to Definition on a clojure.core function like println
2. See in the developer console that an error is thrown like Cannot read property 'document' of undefined

I think it may be coming from the results-doc module, as this was shown when I performed these actions with the code from the PR that doesn't bundle with webpack. With current/bundled Calva, it just shows extension.js:1.