"undefined method `getQuietPeriod' for nil:NilClass" for jobs in folders

[LuciferInLove]

Hello. When I create a job just on View (not in folders), webhook build_now/:project_name works successful. But when I create a job in folder via Folders Plugin, I see the message:

<NoMethodError: undefined method `getQuietPeriod' for nil:NilClass>

Backtrace:

/var/lib/jenkins/plugins/gitlab-hook/WEB-INF/classes/models/api.rb in POST /build_now/:project_name
 project.scheduleBuild2(project.getQuietPeriod(), cause_builder.with(details), actions_builder.with(project, details))
/var/lib/jenkins/plugins/gitlab-hook/WEB-INF/classes/vendor/gems/gems/rack-protection-1.2.0/lib/rack/protection/xss_header.rb in call
 status, headers, body = @app.call(env)
/var/lib/jenkins/plugins/gitlab-hook/WEB-INF/classes/vendor/gems/gems/rack-protection-1.2.0/lib/rack/protection/path_traversal.rb in call
 app.call env
/var/lib/jenkins/plugins/gitlab-hook/WEB-INF/classes/vendor/gems/gems/rack-protection-1.2.0/lib/rack/protection/json_csrf.rb in call
 status, headers, body = app.call(env)
/var/lib/jenkins/plugins/gitlab-hook/WEB-INF/classes/vendor/gems/gems/rack-protection-1.2.0/lib/rack/protection/base.rb in call
 result or app.call(env)
/var/lib/jenkins/plugins/gitlab-hook/WEB-INF/classes/vendor/gems/gems/rack-protection-1.2.0/lib/rack/protection/xss_header.rb in call
 status, headers, body = @app.call(env)
/var/lib/jenkins/plugins/gitlab-hook/WEB-INF/classes/vendor/gems/gems/rack-1.4.1/lib/rack/nulllogger.rb in call
 @app.call(env)
/var/lib/jenkins/plugins/gitlab-hook/WEB-INF/classes/vendor/gems/gems/rack-1.4.1/lib/rack/head.rb in call
 status, headers, body = @app.call(env)
/var/lib/jenkins/plugins/gitlab-hook/WEB-INF/classes/models/root_action.rb in call
 GitlabWebHook::Api.new.call(env)
file:/var/lib/jenkins/plugins/ruby-runtime/WEB-INF/lib/jruby-rack-1.1.13.1.jar!/rack/handler/servlet.rb in call
 self.class.response.new(@app.call(create_env(servlet_env)))
/var/lib/jenkins/plugins/gitlab-hook/WEB-INF/classes/models/crumb_exclusion.rb in process
 chain.doFilter(request, response)