Fix out of bound exception with attributes selection

...classification/controller/ChooseAttributesController.java

...lle/sae/classification/controller/LoadDataController.java

...main/java/fr/univlille/sae/classification/model/Iris.java

...a/fr/univlille/sae/classification/model/LoadableData.java

...n/java/fr/univlille/sae/classification/model/Pokemon.java

.../java/fr/univlille/sae/classification/utils/ViewUtil.java

...a/fr/univlille/sae/classification/view/DataStageView.java

...vlille/sae/classification/view/DataVisualizationView.java