Make sure default user has no username nor password

Former-commit-id: 3305df282ea22d08f09e9c63b1bcce9d416882cf [formerly 7920663664913478abd930448a6c211c556742dc] [formerly 667491e5d07f7b167f6b24318859ffcaeef7823b [formerly f8465edab5]]
Former-commit-id: 8b65f5ec2145873ef725d7cab861f125acda2384 [formerly ea12be024963dccd4eb79cf67e6a0b199eb897bc]
Former-commit-id: d0049f9831d725bc3fde7716462f9a5a092cce83

filemanager.go

@@ -228,6 +228,8 @@ func New(database string, base User) (*FileManager, error) {
 	m.db = db
 
 	// Create the default user, making a copy of the base.
+	base.Username = ""
+	base.Password = ""
 	m.DefaultUser = &base
 	return m, nil
 }