Fix ValidateSet syntax test
Fix ValidateSet syntax test

Get-Help displyies ValidateSet entry in syntax differently
in v5.0 and v5.1 (sic!)
In v5.0 is has type (i.e. <String[]>), but in v5.1 it doesn't.
Now test is agnostic about it

PowerShell/platyPS,PowerShell/platyPS,PowerShell/platyPS