Fix null issue on "notifierPourCorbeilleVirtuelle" function

iparapheur-core/src/main/java/org/adullact/iparapheur/repo/notification/impl/NotificationServiceImpl.java

@@ -1275,7 +1275,10 @@ public class NotificationServiceImpl implements NotificationService {
         NodeRef bureau = nodeUtilsService.getFirstParentOfType(corbeille, ParapheurModel.TYPE_PARAPHEUR);
         String bureauName = (String) nodeService.getProperty(bureau, ContentModel.PROP_TITLE);
         String nomValideur = userUtilsService.getFullname(username);
-        String dossierTitre = (String) nodeService.getProperty(dossier, ContentModel.PROP_TITLE);
+        String dossierTitre = "";
+        if(nodeService.exists(dossier)) {
+            dossierTitre = (String) nodeService.getProperty(dossier, ContentModel.PROP_TITLE);
+        }
 
         Notification notification = new Notification(
                 Notification.Target.current.name(),