Hi Team,

 I have observed an unexpected crash of gitops-operator on OSD platform. Probably because Operator is trying to reconcile an empty configmap.

jfischer@redhat.com can reproduce this issue by creating an empty Argo CD configmap (argocd-cm) in a namespace and then creating an Argo CD CR. Noticed that operator crashed while reconciling the empty configmap.

Error:
goroutine 1873 [running]:
k8s.io/apimachinery/pkg/util/runtime.logPanic(0x1769d40, 0x1b43340)
/remote-source/deps/gomod/pkg/mod/k8s.io/apimachinery@v0.18.3/pkg/util/runtime/runtime.go:74 +0xa6
k8s.io/apimachinery/pkg/util/runtime.HandleCrash(0x0, 0x0, 0x0)
/remote-source/deps/gomod/pkg/mod/k8s.io/apimachinery@v0.18.3/pkg/util/runtime/runtime.go:48 +0x86
panic(0x1769d40, 0x1b43340)
/usr/lib/golang/src/runtime/panic.go:965 +0x1b9
github.com/argoproj-labs/argocd-operator/pkg/controller/argocd.(*ReconcileArgoCD).reconcileExistingArgoConfigMap(0xc0008f4000, 0xc008c18780, 0xc00850e000, 0x0, 0x0)
/remote-source/deps/gomod/pkg/mod/github.com/argoproj-labs/argocd-operator@v0.0.16-0.20210715041124-bb75775953f8/pkg/controller/argocd/configmap.go:420 +0x53e
github.com/argoproj-labs/argocd-operator/pkg/controller/argocd.(*ReconcileArgoCD).reconcileArgoConfigMap(0xc0008f4000, 0xc00850e000, 0x0, 0x0)
/remote-source/deps/gomod/pkg/mod/github.com/argoproj-labs/argocd-operator@v0.0.16-0.20210715041124-bb75775953f8/pkg/controller/argocd/configmap.go:312 +0x11af
github.com/argoproj-labs/argocd-operator/pkg/controller/argocd.(*ReconcileArgoCD).reconcileConfigMaps(0xc0008f4000, 0xc00850e000, 0x17, 0x0)
/remote-source/deps/gomod/pkg/mod/github.com/argoproj-labs/argocd-operator@v0.0.16-0.20210715041124-bb75775953f8/pkg/controller/argocd/configmap.go:250 +0x39
github.com/argoproj-labs/argocd-operator/pkg/controller/argocd.(*ReconcileArgoCD).reconcileResources(0xc0008f4000, 0xc00850e000, 0xc000042068, 0xc000ec8680)
runtime@v0.6.0/pkg/internal/controller/controller.go:193 +0x32d
panic: assignment to entry in nil map [recovered]
panic: assignment to entry in nil map

Acceptance Criteria:
Operator should not crash.