panic: rare nil metric influx output

[goller]

Relevant telegraf.conf:

    [[outputs.influxdb]]
      urls = ["$MONITOR_HOST"]
      database = "$MONITOR_DATABASE"
      retention_policy = "$MONITOR_RP"
      write_consistency = "any"
      timeout = "5s"
      username = "$MONITOR_USERNAME"
      password = "$MONITOR_PASSWORD"
    [[outputs.influxdb_v2]]
      urls = ["$MONITOR_HOST_V2"]
      token = "$MONITOR_TOKEN"
      organization = "$MONITOR_DATABASE"
      bucket = "$MONITOR_RP"
      timeout = "5s"
    [global_tags]
      env = "$ENV"
      hostname = "$HOSTNAME"
      nodename = "$NODENAME"
      role = "gateway"
    [[inputs.prometheus]]
      urls = ["http://127.0.0.1:9999/metrics"]

System info:

Telegraf Version: 1.9.5
OS: Linux

Steps to reproduce:

Extremely rare. Monitored processes are under heavy load with many metrics, yet, this seems to have happened only once.

Actual behavior:

Panic:

2019-03-01T20:01:45Z E! [agent] Error writing to output [influxdb_v2]: could not write any address
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x90 pc=0x86219a]
goroutine 4923 [running]:
github.com/influxdata/telegraf/plugins/serializers/influx.(*Serializer).buildHeader(0xc0008f2000, 0x0, 0x0, 0xc000a9e180, 0x300000002)
    /go/src/github.com/influxdata/telegraf/plugins/serializers/influx/influx.go:143 +0x4a
github.com/influxdata/telegraf/plugins/serializers/influx.(*Serializer).writeMetric(0xc0008f2000, 0x2500e80, 0xc002cf33b0, 0x0, 0x0, 0x7f360c6d9da8, 0x1)
    /go/src/github.com/influxdata/telegraf/plugins/serializers/influx/influx.go:200 +0x5a
github.com/influxdata/telegraf/plugins/serializers/influx.(*Serializer).Write(0xc0008f2000, 0x2500e80, 0xc002cf33b0, 0x0, 0x0, 0x7f3623295d80, 0x0, 0x4301a3)
    /go/src/github.com/influxdata/telegraf/plugins/serializers/influx/influx.go:124 +0x53
github.com/influxdata/telegraf/plugins/serializers/influx.(*reader).Read(0xc000766090, 0xc00116a000, 0x8000, 0x8000, 0x8000, 0x8000, 0xc001e423b8)
    /go/src/github.com/influxdata/telegraf/plugins/serializers/influx/reader.go:52 +0xea
io.copyBuffer(0x2500f40, 0xc0002bf760, 0x2501ba0, 0xc000766090, 0xc00116a000, 0x8000, 0x8000, 0x0, 0xc000900000, 0x4)
    /usr/local/go/src/io/io.go:402 +0x125
io.Copy(0x2500f40, 0xc0002bf760, 0x2501ba0, 0xc000766090, 0x45e836, 0xc001ac5080, 0xc0008f8120)
    /usr/local/go/src/io/io.go:364 +0x5a
github.com/influxdata/telegraf/internal.CompressWithGzip.func1(0xc0002bf760, 0x2501ba0, 0xc000766090, 0xc001428090, 0xc002e17fe8)
    /go/src/github.com/influxdata/telegraf/internal/internal.go:317 +0x4f
created by github.com/influxdata/telegraf/internal.CompressWithGzip
    /go/src/github.com/influxdata/telegraf/internal/internal.go:316 +0x1b1

Additional info:

I'm not totally certain if this happened on upgrade from 1.9.2 to 1.9.5