message: fix: Support root container access in regex.json
diff: "base": { "@id": "urn:solid-server:default:variable:baseUrl" },
  "storeMap": [
  {
  - "RegexRouterRule:_storeMap_key": "^/\\.acl$",
  + "RegexRouterRule:_storeMap_key": "^/(\\.acl)?$",
  "RegexRouterRule:_storeMap_value": { "@id": "urn:solid-server:default:SparqlResourceStore" }
  },
  {
  