95ab28c frontend: don't generate 'modules' in build-job unnecessarily

Authored and Committed by praiskup 4 years ago
    frontend: don't generate 'modules' in build-job unnecessarily
    
    When the 'module_toggle' is empty, it's not expected to put it into the
    build job task.
    
    Complements: ddb706f92838dd167658be549761c71e00b2652e