fix: core full stop

core/main.go

@@ -82,12 +82,9 @@ func (c *Core) Start(sbConfig []byte) error {
 }
 
 func (c *Core) Stop() error {
-	if c.isRunning {
 	c.isRunning = false
 	return c.instance.Close()
 }
-	return nil
-}
 
 func (c *Core) IsRunning() bool {
 	return c.isRunning