ERP5Workflow: Remove unused variable_default_value and use...

ERP5Workflow: Remove unused variable_default_value and use variable_default_expression instead (!1378).
Status Job ID Name Coverage
  External
failed ERP5.CodingStyleTest-TestRunner1

00:48:56

failed ERP5.PerformanceTest-TestRunner1

00:28:55

failed ERP5.UnitTest-TestRunner1

02:35:41