ScaledJob: panic ifminReplicaCount is specified & maxReplicaCount is not set

[zroubalik]

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ScaledJob: panic ifminReplicaCount is specified & maxReplicaCount is not set

Expected Behavior

not panic

Actual Behavior

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=0x0 pc=0x22e3ab1]

goroutine 48 [running]:
github.com/kedacore/keda/v2/apis/keda/v1alpha1.ScaledJob.MinReplicaCount(...)
/Users/zroubali/go/src/github.com/kedacore/keda/apis/keda/v1alpha1/scaledjob_types.go:126
github.com/kedacore/keda/v2/apis/keda/v1alpha1.TestScaledJob.func1(0xc000503d40)
/Users/zroubali/go/src/github.com/kedacore/keda/apis/keda/v1alpha1/scaledjob_types_test.go:59 +0x231

Steps to Reproduce the Problem

1. deploy ScaledJob with min replicas set and not max replicas set

Anything else?

#4541 (comment)