add default user signatures

lib/ability.rb

@@ -11,6 +11,7 @@ class Ability
     can :manage, User, account_id: user.account_id
     can :manage, EncryptedConfig, account_id: user.account_id
     can :manage, AccountConfig, account_id: user.account_id
+    can :manage, UserConfig, user_id: user.id
     can :manage, Account, id: user.account_id
     can :manage, AccessToken, user_id: user.id
   end