WPA Beanstalk is crashing sometimes with nil pointer error. #88
Description
WPA is crashing and restarting sometimes with the nil pointer error
I0702 11:51:51.353487 1 controller.go:484] dev-call_otp_updater-crstg1 minWorkers=0, maxDisruptableWorkers=0
I0702 11:51:51.353505 1 controller.go:356] dev-call_otp_updater-crstg1: messages: 0, idle: 0, desired: 0
I0702 11:51:51.353513 1 controller.go:593] crstg1/25-29871-otpcallupdater-praccomm-api: WPA status is already up to date
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x1202436]
goroutine 45213 [running]:
github.com/beanstalkd/go-beanstalk.(*Conn).cmd(0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x16c2531, 0xa, 0xc00d553a38, 0x1, ...)
/src/vendor/github.com/beanstalkd/go-beanstalk/conn.go:76 +0x66
github.com/beanstalkd/go-beanstalk.(*Tube).Stats(0xc00d553a90, 0x34, 0xc00085c1de, 0x16)
/src/vendor/github.com/beanstalkd/go-beanstalk/tube.go:93 +0xcf
github.com/practo/k8s-worker-pod-autoscaler/pkg/queue.(*beanstalkClient).executeGetStats(0xc00734c440, 0xc00d553b98, 0x139935a, 0x1541140, 0x15dc740)
/src/pkg/queue/beanstalk.go:123 +0x90
github.com/practo/k8s-worker-pod-autoscaler/pkg/queue.(*beanstalkClient).getStats(0xc00734c440, 0xc000a2ec00, 0x34, 0x1a0bec0, 0xc00734c440)
/src/pkg/queue/beanstalk.go:144 +0x2f
github.com/practo/k8s-worker-pod-autoscaler/pkg/queue.(*Beanstalk).getMessages(0xc00017e090, 0xc000a2ec00, 0x34, 0x446235, 0xa1bc22, 0xc00e35a450)
/src/pkg/queue/beanstalk.go:262 +0x8a
github.com/practo/k8s-worker-pod-autoscaler/pkg/queue.(*Beanstalk).poll(0xc00017e090, 0xc0014c3b00, 0x26, 0xc000a2ec1e, 0x16, 0xc00b599a70, 0x6, 0xc000a2ec00, 0x34, 0xc000a2ec0c, ...)
/src/pkg/queue/beanstalk.go:351 +0x75
github.com/practo/k8s-worker-pod-autoscaler/pkg/queue.(*Poller).runPollThread(0xc00017e0f0, 0xc0014c3b00, 0x26)
/src/pkg/queue/poller.go:46 +0x88
created by github.com/practo/k8s-worker-pod-autoscaler/pkg/queue.(*Poller).Run
/src/pkg/queue/poller.go:93 +0x209