If run-time is empty then no run-time tag should be created

Current Situation

• The Job Editor creates a <run_time/> element in case that no run-time is specified.
• The same behavior applies to <params/> if no parameters are specified.

Desired Behavior

• Empty elements should not be created.

Resolution

• The behavior remains unchanged.
• The handling of empty elements is specified by the configuration XSD schema. Due to the internal processing of JobScheduler such elements are required.
• There is no impact of empty elements on the processing of JobScheduler objects.