[PE-D][Tester D] Zero is not accepted as a valid quantity

[soc-se-bot]

The error message says that quantity should be non-negative integer. Zero is non negative but is not accepted.

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Labels: type.FunctionalityBug severity.VeryLow original: currynia/ped#2

[jialegitgud]

For business constraints reasons, the quantity should never be 0. Hence, should be updated in UG/DG to reflect this.