Fix error indicator

src/language/ast/ASTNodeAffectationExpressionBuilder.cpp

@@ -268,7 +268,8 @@ ASTNodeAffectationExpressionBuilder::ASTNodeAffectationExpressionBuilder(ASTNode
         break;
       }
       default: {
-        throw parse_error("unexpected error: undefined value type for affectation", std::vector{n.begin()});
+        throw parse_error("unexpected error: undefined value type for affectation",
+                          std::vector{n.children[0]->begin()});
       }
       }
     };