Better alert for shacl validation

src/main/java/fr/inra/po2vocabmanager/MainApp.java

@@ -1357,7 +1357,7 @@ public class MainApp extends Application implements Launcher  {
                     long timeElapsed = (long)((finish - start)*0.000001);
 
                     Platform.runLater(() -> {
-                        Alert SHACLValidationEndMessage = new Alert(AlertType.INFORMATION);
+                        Alert SHACLValidationEndMessage = r.success() ? new Alert(AlertType.CONFIRMATION) : new Alert(AlertType.WARNING);
                         SHACLValidationEndMessage.setResizable(true);
                         SHACLValidationEndMessage.setTitle("SHACL validation ended");
                         SHACLValidationEndMessage.setHeaderText("REPORT");