Handle missing "build" inputs

Dependencies

• [2] 2WRTOU2Z Cleanup
• [3] OOQ2D3KC * Refactoring: move fetchInput out of hydra_scheduler into a separate
• [4] 3XTHEUMP * Implemented the clone feature.

Change contents

• replacement in src/lib/Hydra/Helper/AddBuilds.pm at line 598
  [2.1378]→[2.1378:1406](∅→∅)
  − $input->{type} = $type;
  [2.1378]

  [2.1406]
  + $input->{type} = $type if defined $input;