update dependencies (#6267)

Signed-off-by: hongming <coder.scala@gmail.com>

vendor/golang.org/x/time/rate/rate.go

@@ -99,8 +99,9 @@ func (lim *Limiter) Tokens() float64 {
 // bursts of at most b tokens.
 func NewLimiter(r Limit, b int) *Limiter {
 	return &Limiter{
-		limit: r,
-		burst: b,
+		limit:  r,
+		burst:  b,
+		tokens: float64(b),
 	}
 }
 
@@ -344,18 +345,6 @@ func (lim *Limiter) reserveN(t time.Time, n int, maxFutureReserve time.Duration)
 			tokens:    n,
 			timeToAct: t,
 		}
-	} else if lim.limit == 0 {
-		var ok bool
-		if lim.burst >= n {
-			ok = true
-			lim.burst -= n
-		}
-		return Reservation{
-			ok:        ok,
-			lim:       lim,
-			tokens:    lim.burst,
-			timeToAct: t,
-		}
 	}
 
 	t, tokens := lim.advance(t)