Merge pull request #3158 from floriank/fix/20484-clear-option-in-select

[20484] Add a name to the empty options in dropdowns in Work Package details pane

frontend/app/work_packages/services/work-package-field-service.js

@@ -146,7 +146,10 @@ module.exports = function(
     });
 
     if (!WorkPackageFieldService.isRequired(workPackage, field)) {
-      var arrayWithEmptyOption = [{ href: null }];
+      var arrayWithEmptyOption = [{
+        href: null,
+        name: I18n.t('js.inplace.null_value_label')
+      }];
       options = arrayWithEmptyOption.concat(options);
     }