import_tasks: ev_user.yml and import_tasks: ev_group.yml may not be executed

[berndfinger]

In case sap_hana_deployment_hana_userid or sap_hana_deployment_hana_groupid are undefined, the condition is not met so the import_tasks statement will not be executed. We should use the following when condition instead (example for ev_user.yml):

• ((sap_hana_deployment_hana_userid is undefined) or (sap_hana_deployment_hana_userid is none) or (sap_hana_deployment_hana_userid | trim == '') )