Update

vendor/tailscale.com/util/ringlog/ringlog.go

@@ -1,4 +1,4 @@
-// Copyright (c) Tailscale Inc & AUTHORS
+// Copyright (c) Tailscale Inc & contributors
 // SPDX-License-Identifier: BSD-3-Clause
 
 // Package ringlog contains a limited-size concurrency-safe generic ring log.
@@ -70,7 +70,12 @@ func (rb *RingLog[T]) Len() int {
 }
 
 // Clear will empty the ring log.
+//
+// It does nothing if rb is nil.
 func (rb *RingLog[T]) Clear() {
+	if rb == nil {
+		return
+	}
 	rb.mu.Lock()
 	defer rb.mu.Unlock()
 	rb.pos = 0