Console fails to load on Wildfly 10

[ammendonca]

After the change from #2898, the console does not load due to a failure (Uncaught SyntaxError: Unexpected token o in JSON at position 1) while loading the configuration file. It works on AS7.

This happens because AS7 sends the file as plaintext (thus it needs to be parsed to JSON with JSON.parse(response)), while WF10 sends it as application/json (where no parsing is necessary and trying to do so, will cause such error).