panic: runtime error: integer divide by zero

[rafalbigaj]

/kind bug

What steps did you take and what happened:
When PipelineLoop step is set to 0, the process panics with:

goroutine 62 [running]:
github.com/kubeflow/kfp-tekton/tekton-catalog/pipeline-loops/pkg/reconciler/pipelinelooprun.computeIterations(0xc0009b01c0, 0xc0009b01c0)
	github.com/kubeflow/kfp-tekton/tekton-catalog/pipeline-loops@v0.0.0-20220120185053-793854829e7e/pkg/reconciler/pipelinelooprun/pipelinelooprun.go:812 +0x6da
github.com/kubeflow/kfp-tekton/tekton-catalog/pipeline-loops/pkg/reconciler/pipelinelooprun.(*Reconciler).reconcile(0xc0002d48a0, {0x2893258, 0xc003807a40}, 0xc00381e240, 0xc0037e72a8)
	github.com/kubeflow/kfp-tekton/tekton-catalog/pipeline-loops@v0.0.0-20220120185053-793854829e7e/pkg/reconciler/pipelinelooprun/pipelinelooprun.go:310 +0x169
github.com/kubeflow/kfp-tekton/tekton-catalog/pipeline-loops/pkg/reconciler/pipelinelooprun.(*Reconciler).ReconcileKind(0x0, {0x2893258, 0xc003807a40}, 0xc00381e240)
	github.com/kubeflow/kfp-tekton/tekton-catalog/pipeline-loops@v0.0.0-20220120185053-793854829e7e/pkg/reconciler/pipelinelooprun/pipelinelooprun.go:180 +0xcb5
github.com/tektoncd/pipeline/pkg/client/injection/reconciler/pipeline/v1alpha1/run.(*reconcilerImpl).Reconcile(0xc000d51400, {0x2893258, 0xc003807a10}, {0xc003815180, 0x64})
	github.com/tektoncd/pipeline@v0.32.1/pkg/client/injection/reconciler/pipeline/v1alpha1/run/reconciler.go:239 +0x6d7
knative.dev/pkg/controller.(*Impl).processNextWorkItem(0xc0002d5740)
	knative.dev/pkg@v0.0.0-20220302134643-d2cdc682d974/controller/controller.go:535 +0x5a5
knative.dev/pkg/controller.(*Impl).RunContext.func3()
	knative.dev/pkg@v0.0.0-20220302134643-d2cdc682d974/controller/controller.go:484 +0x68
created by knative.dev/pkg/controller.(*Impl).RunContext
	knative.dev/pkg@v0.0.0-20220302134643-d2cdc682d974/controller/controller.go:482 +0x2de

What did you expect to happen:

Use default step value: 1 in case of 0 provided.

Additional information:
[Miscellaneous information that will assist in solving the issue.]

Environment:

• Python Version (use python --version):
• SDK Version:
• Tekton Version (use tkn version): v0.30.1
• Kubernetes Version (use kubectl version):
• OS (e.g. from /etc/os-release):