cmd: disable zap log sampling (#66)

Skipping log lines is not safe to be used by default. Notice that
s3-authmate doesn't have this problem because of the way it constructs
its settings.

See also:
 * nspcc-dev/neofs-node#3011
 * nspcc-dev/neo-go#598

cmd/neofs-oauthz/config.go

@@ -146,6 +146,7 @@ func newLogger(v *viper.Viper) (*zap.Logger, error) {
 		}
 	}
 
+	c.Sampling = nil
 	if term.IsTerminal(int(os.Stdout.Fd())) {
 		c.EncoderConfig.EncodeTime = zapcore.ISO8601TimeEncoder
 	} else {