FIX : Log in work again

Sources/dafl_project_flutter/lib/controller/controller.dart

@@ -101,8 +101,14 @@ class Controller {
     _dataBaseService.save(userToSave);
   }
 
-  load(String username, String password) async {
-    //TODO : call database methode + create user
+  Future<bool> load(String username, String password) async {
+    User? newUser = await _dataBaseService.load(username, password);
+
+    if(newUser == null)
+      return false;
+    else
+      _currentUser = newUser;
+      return true;
   }
 
   changeUsername(String newName) {

Sources/dafl_project_flutter/lib/views/pages/sign_in/p_sign_in.dart

@@ -258,7 +258,7 @@ class _SignInPageState extends State<SignInPage> {
     } else if (password == "") {
       notify(4, context);
     } else if(await MyApp.controller
-        .load(userNameTextField.text, passwordTextField.text) != null) {
+        .load(userNameTextField.text, passwordTextField.text)) {
         Navigator.of(context).push(
           PageTransition(
               type: PageTransitionType.fade,