Eventrouter in OpenShift Container Platform is crashing

Issue

• pod kube-eventrouter in logging-eventrouter deployment is crashing with below stack-trace:

E0910 10:53:39.323114       1 runtime.go:66] Observed a panic: "invalid memory address or nil pointer dereference" (runtime error: invalid memory address or nil pointer dereference)
/builddir/build/BUILD/eventrouter-5bd925143c4263d18cb33bfc3f3edbcf4267b2a5/src/github.com/openshift/eventrouter/vendor/k8s.io/apimachinery/pkg/util/runtime/runtime.go:72
/builddir/build/BUILD/eventrouter-5bd925143c4263d18cb33bfc3f3edbcf4267b2a5/src/github.com/openshift/eventrouter/vendor/k8s.io/apimachinery/pkg/util/runtime/runtime.go:65
/builddir/build/BUILD/eventrouter-5bd925143c4263d18cb33bfc3f3edbcf4267b2a5/src/github.com/openshift/eventrouter/vendor/k8s.io/apimachinery/pkg/util/runtime/runtime.go:51
/usr/lib/golang/src/runtime/asm_amd64.s:514
/usr/lib/golang/src/runtime/panic.go:489
/usr/lib/golang/src/runtime/panic.go:63
/usr/lib/golang/src/runtime/signal_unix.go:290
/builddir/build/BUILD/eventrouter-5bd925143c4263d18cb33bfc3f3edbcf4267b2a5/src/github.com/openshift/eventrouter/eventrouter.go:152
/builddir/build/BUILD/eventrouter-5bd925143c4263d18cb33bfc3f3edbcf4267b2a5/src/github.com/openshift/eventrouter/eventrouter.go:113
/builddir/build/BUILD/eventrouter-5bd925143c4263d18cb33bfc3f3edbcf4267b2a5/src/github.com/openshift/eventrouter/eventrouter.go:86
/builddir/build/BUILD/eventrouter-5bd925143c4263d18cb33bfc3f3edbcf4267b2a5/src/github.com/openshift/eventrouter/vendor/k8s.io/client-go/tools/cache/controller.go:192
<autogenerated>:54
/builddir/build/BUILD/eventrouter-5bd925143c4263d18cb33bfc3f3edbcf4267b2a5/src/github.com/openshift/eventrouter/vendor/k8s.io/client-go/tools/cache/shared_informer.go:547
/usr/lib/golang/src/runtime/asm_amd64.s:2197
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
    panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x20 pc=0x11c2239]

goroutine 35 [running]:
github.com/openshift/eventrouter/vendor/k8s.io/apimachinery/pkg/util/runtime.HandleCrash(0x0, 0x0, 0x0)
    /builddir/build/BUILD/eventrouter-5bd925143c4263d18cb33bfc3f3edbcf4267b2a5/src/github.com/openshift/eventrouter/vendor/k8s.io/apimachinery/pkg/util/runtime/runtime.go:58 +0x126
panic(0x130ff20, 0x1d2c5b0)
    /usr/lib/golang/src/runtime/panic.go:489 +0x2cf
main.prometheusEvent(0xc420f74670)
    /builddir/build/BUILD/eventrouter-5bd925143c4263d18cb33bfc3f3edbcf4267b2a5/src/github.com/openshift/eventrouter/eventrouter.go:152 +0xe9
main.(*EventRouter).addEvent(0xc4203f9040, 0x1471800, 0xc420f74670)
    /builddir/build/BUILD/eventrouter-5bd925143c4263d18cb33bfc3f3edbcf4267b2a5/src/github.com/openshift/eventrouter/eventrouter.go:113 +0x3c
main.(*EventRouter).(main.addEvent)-fm(0x1471800, 0xc420f74670)
    /builddir/build/BUILD/eventrouter-5bd925143c4263d18cb33bfc3f3edbcf4267b2a5/src/github.com/openshift/eventrouter/eventrouter.go:86 +0x3e
github.com/openshift/eventrouter/vendor/k8s.io/client-go/tools/cache.ResourceEventHandlerFuncs.OnAdd(0xc42018efb0, 0xc42018efd0, 0xc42018efe0, 0x1471800, 0xc420f74670)
    /builddir/build/BUILD/eventrouter-5bd925143c4263d18cb33bfc3f3edbcf4267b2a5/src/github.com/openshift/eventrouter/vendor/k8s.io/client-go/tools/cache/controller.go:192 +0x49
github.com/openshift/eventrouter/vendor/k8s.io/client-go/tools/cache.(*ResourceEventHandlerFuncs).OnAdd(0xc4202af3e0, 0x1471800, 0xc420f74670)
    <autogenerated>:54 +0x73
github.com/openshift/eventrouter/vendor/k8s.io/client-go/tools/cache.(*processorListener).run(0xc4200a66e0, 0xc4201a4480)
    /builddir/build/BUILD/eventrouter-5bd925143c4263d18cb33bfc3f3edbcf4267b2a5/src/github.com/openshift/eventrouter/vendor/k8s.io/client-go/tools/cache/shared_informer.go:547 +0x2f6
created by github.com/openshift/eventrouter/vendor/k8s.io/client-go/tools/cache.(*sharedProcessor).run
    /builddir/build/BUILD/eventrouter-5bd925143c4263d18cb33bfc3f3edbcf4267b2a5/src/github.com/openshift/eventrouter/vendor/k8s.io/client-go/tools/cache/shared_informer.go:402 +0xb3