Fix TestUserWorkspaceHierarchy.testClientSideUser1 randomly failing against MongoDB

Failed to save session, 98c729b1-dfbf-4c3d-96b0-a1a3aaad81b6
Pile d'exécution
org.nuxeo.ecm.core.api.ConcurrentUpdateException: Failed to save session, 98c729b1-dfbf-4c3d-96b0-a1a3aaad81b6
	at org.nuxeo.ecm.core.storage.mongodb.MongoDBConnection.updateState(MongoDBConnection.java:500)
	at org.nuxeo.ecm.core.storage.dbs.DBSTransactionState.save(DBSTransactionState.java:883)
	at org.nuxeo.ecm.core.storage.dbs.DBSSession.save(DBSSession.java:239)
	at jdk.internal.reflect.GeneratedMethodAccessor49.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.nuxeo.ecm.core.storage.dbs.DBSRepositoryBase$DBSSessionInvoker.invoke(DBSRepositoryBase.java:487)
	at com.sun.proxy.$Proxy80.save(Unknown Source)
	at org.nuxeo.ecm.core.api.AbstractSession.save(AbstractSession.java:1510)
	at org.nuxeo.drive.hierarchy.userworkspace.TestUserWorkspaceHierarchy.resetPermissions(TestUserWorkspaceHierarchy.java:540)
	at org.nuxeo.drive.hierarchy.userworkspace.TestUserWorkspaceHierarchy.tearDown(TestUserWorkspaceHierarchy.java:251)