fixed cleanup deadlock

jwt.go

@@ -175,12 +175,12 @@ func (jwt *JWT) clean() {
 		}
 		now := time.Now().UTC().Unix()
 		jwt.Lock()
-		defer jwt.Unlock()
 		for k, v := range jwt.list {
 			if now > v {
 				delete(jwt.list, k)
 			}
 		}
+		jwt.Unlock()
 	}
 }