panic in pgbouncer plugin

[jsnjack]

Relevant telegraf.conf:

[[inputs.pgbouncer]]
  ## specify address via a url matching:
  ##   postgres://[pqgotest[:password]]@localhost[/dbname]\
  ##       ?sslmode=[disable|verify-ca|verify-full]
  ## or a simple string:
  ##   host=localhost user=pqotest password=... sslmode=... dbname=app_production
  ##
  ## All connection parameters are optional.
  ##
  address = "host=localhost port=6432 user=dbuser database=pgbouncer"

System info:

Debian 8, telegraf 1.11.0-1, pgbouncer 1.5.4

Steps to reproduce:

1. Enable pgbouncer input

Expected behavior:

Telegraf starts to report data

Actual behavior:

Telegraf is not able to start

Additional info:

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x8 pc=0x15ac136]
goroutine 43 [running]:
github.com/influxdata/telegraf/plugins/inputs/pgbouncer.(*PgBouncer).Gather(0xc000556cd0, 0x2a32740, 0xc000223660, 0x0, 0x0)
/go/src/github.com/influxdata/telegraf/plugins/inputs/pgbouncer/pgbouncer.go:105 +0x746
github.com/influxdata/telegraf/internal/models.(*RunningInput).Gather(0xc000139300, 0x2a32740, 0xc000223660, 0x2a17b80, 0xc000093ec0)
/go/src/github.com/influxdata/telegraf/internal/models/running_input.go:86 +0x6d
github.com/influxdata/telegraf/agent.(*Agent).gatherOnce.func1(0xc00027c0c0, 0xc000139300, 0x2a32740, 0xc000223660)
/go/src/github.com/influxdata/telegraf/agent/agent.go:299 +0x3f
created by github.com/influxdata/telegraf/agent.(*Agent).gatherOnce
/go/src/github.com/influxdata/telegraf/agent/agent.go:298 +0xdc