I have encountered some issues with config.json

1. solid init doesn't save serverUri to config.json
2. setting "multiuser": true & "webid": false results in

  solid:get / on idp.hackers4peace.net +3s
  solid:get GET -- Error: 404 Can't find file requested: [object Object] +2ms

3. setting "multiuser": false and "webid": false results in

  solid:get / on idp.hackers4peace.net +7ms
  solid:get    sending data browser file: /usr/lib/node_modules/solid-server/static/databrowser.html +31ms

4. setting "multiuser": false and "webid": true and "auth": "oidc" finally leads to expected
   

I plan to use this deployment only as OIDC Issuer for external WebIDs, it will never act as Resource Server. Another deployment on different domain will act as Resource Server which will also include WebID Profile, but will not act as OIDC Issuer. Currently both don't require "multiuser": true, but later I might enable it.

I miss combination of configuration options to clearly define:

• only act as OIDC Issuer, no Resource Server
• only act as Resource Server, no OIDC Issuer

I would also like to disable WebID-TLS on those both servers, only using WebID-OIDC.

Related to #672