Invalid memory address or nil pointer dereference in processRequestedAppOperation

[alexmt]

Describe the bug

Controller fails with invalid memory address or nil pointer dereference method:

runtime/debug.Stack(0xc020a9b6b0, 0x2a125c0, 0x52f8d20)
    /usr/local/go/src/runtime/debug/stack.go:24 +0x9f
github.com/argoproj/argo-cd/v2/controller.(*ApplicationController).processAppOperationQueueItem.func1(0xc0006a3980, 0x28fa600, 0xc10015e270)
    /go/src/github.com/argoproj/argo-cd/controller/appcontroller.go:687 +0x8c
panic(0x2a125c0, 0x52f8d20)
    /usr/local/go/src/runtime/panic.go:965 +0x1b9
github.com/argoproj/argo-cd/v2/controller.(*ApplicationController).processRequestedAppOperation.func1(0xc0939a5960, 0xc020a9bbe0, 0xc0006a3980, 0xc098444000)
    /go/src/github.com/argoproj/argo-cd/controller/appcontroller.go:1007 +0xf1
panic(0x2a125c0, 0x52f8d20)
    /usr/local/go/src/runtime/panic.go:965 +0x1b9
github.com/argoproj/argo-cd/v2/controller.(*ApplicationController).processRequestedAppOperation(0xc0006a3980, 0xc098444000)
    /go/src/github.com/argoproj/argo-cd/controller/appcontroller.go:1046 +0x1b2
github.com/argoproj/argo-cd/v2/controller.(*ApplicationController).processAppOperationQueueItem(0xc0006a3980, 0x203001)
    /go/src/github.com/argoproj/argo-cd/controller/appcontroller.go:719 +0x64c
github.com/argoproj/argo-cd/v2/controller.(*ApplicationController).Run.func4()
    /go/src/github.com/argoproj/argo-cd/controller/appcontroller.go:630 +0x36
k8s.io/apimachinery/pkg/util/wait.BackoffUntil.func1(0xc000dbd0e0)
    /go/pkg/mod/k8s.io/apimachinery@v0.21.0/pkg/util/wait/wait.go:155 +0x5f
k8s.io/apimachinery/pkg/util/wait.BackoffUntil(0xc000dbd0e0, 0x3c368a0, 0xc000642300, 0x1, 0xc0007e4e40)
    /go/pkg/mod/k8s.io/apimachinery@v0.21.0/pkg/util/wait/wait.go:156 +0x9b
k8s.io/apimachinery/pkg/util/wait.JitterUntil(0xc000dbd0e0, 0x3b9aca00, 0x0, 0x1, 0xc0007e4e40)
    /go/pkg/mod/k8s.io/apimachinery@v0.21.0/pkg/util/wait/wait.go:133 +0x98
k8s.io/apimachinery/pkg/util/wait.Until(0xc000dbd0e0, 0x3b9aca00, 0xc0007e4e40)
    /go/pkg/mod/k8s.io/apimachinery@v0.21.0/pkg/util/wait/wait.go:90 +0x4d
created by github.com/argoproj/argo-cd/v2/controller.(*ApplicationController).Run
    /go/src/github.com/argoproj/argo-cd/controller/appcontroller.go:629 +0x51f

To Reproduce

No clear steps to reproduce

Expected behavior

No panics in controller

Version

v2.1.4