Quiet two little log annoyances.

ipn/local.go

@@ -215,7 +215,11 @@ func (b *LocalBackend) Start(opts Options) error {
 			b.mu.Lock()
 			if b.netMapCache != nil {
 				diff := newSt.NetMap.ConciseDiffFrom(b.netMapCache)
-				b.logf("netmap diff:\n%v\n", diff)
+				if strings.TrimSpace(diff) == "" {
+					b.logf("netmap diff: (none)")
+				} else {
+					b.logf("netmap diff:\n%v\n", diff)
+				}
 			}
 			b.netMapCache = newSt.NetMap
 			b.mu.Unlock()

netcheck/netcheck.go

@@ -233,7 +233,7 @@ func (c *Client) GetReport(ctx context.Context) (*Report, error) {
 		return gotEP4 != ""
 	}
 	add := func(server, ipPort string, d time.Duration) {
-		c.logf("%s says we are %s (in %v)", server, ipPort, d)
+		c.logf("%s says we are %s (in %v)", server, ipPort, d.Round(time.Millisecond))
 
 		ua, err := net.ResolveUDPAddr("udp", ipPort)
 		if err != nil {