remove roles, as a simplification

data/config/securitySettings.json

@@ -1,16 +1,15 @@
 {
     "jwt_secret":"esp8266-react",
-    "roles": ["admin", "guest"],
     "users": [
         {
             "username": "admin",
             "password": "admin",
-            "role": "admin"
+            "admin": true
         },
         {
             "username": "guest",
             "password": "guest",
-            "role": "guest"
+            "admin": false
         }
     ]
 }