RS promote a project broker's candidate to member

<dispatchinfo>
	<componentinfo>
		<compname>ffo_main_null</compname>
		<compclass>org.olat.core.gui.components.form.flexible.impl.FormWrapperContainer</compclass>
		<extendedinfo>n/a</extendedinfo>
		<event>
			<class&gt;org.olat.core.gui.control.Event</class&gt;
			<command>validation ok</command>
			<tostring>com:validation ok,org.olat.core.gui.control.Event@d62b3f02</tostring>
		</event>
	</componentinfo>
	<controllerinfo>
		<controllername>org.olat.core.util.mail.MailTemplateForm</controllername>
		<controllername>org.olat.admin.securitygroup.gui.WaitingGroupController</controllername>
		<controllername>org.olat.course.nodes.projectbroker.ProjectGroupController</controllername>
		<controllername>org.olat.course.nodes.projectbroker.ProjectListController</controllername>
		<controllername>org.olat.course.run.RunMainController</controllername>
		<controllername>org.olat.course.run.CourseRuntimeController</controllername>
		<controllername>org.olat.core.commons.fullWebApp.BaseFullWebappController</controllername>
	</controllerinfo>
</dispatchinfo>

Throwable: org.hibernate.LazyInitializationException

message:could not initialize proxy - no Session,org.hibernate.LazyInitializationException
  at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:165)
  at org.hibernate.proxy.AbstractLazyInitializer.getImplementation(AbstractLazyInitializer.java:286)
  at org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer.invoke(JavassistLazyInitializer.java:185)
  at org.olat.group.BusinessGroupImpl_$$_jvstdb1_17.getKey(BusinessGroupImpl_$$_jvstdb1_17.java)
  at org.olat.group.manager.BusinessGroupDAO.loadForUpdate(BusinessGroupDAO.java:237)
  at org.olat.group.manager.BusinessGroupServiceImpl.addParticipants(BusinessGroupServiceImpl.java:978)
  at org.olat.course.nodes.projectbroker.service.ProjectGroupManagerImpl.acceptCandidates(ProjectGroupManagerImpl.java:265)
  at org.olat.course.nodes.projectbroker.ProjectGroupController.handleCandidateGroupEvent(ProjectGroupController.java:172)
  at org.olat.course.nodes.projectbroker.ProjectGroupController.event(ProjectGroupController.java:152)
  at org.olat.core.gui.control.DefaultController$1.run(DefaultController.java:246)