fix generator default value.

lib/src/kdbx_format.dart

@@ -278,11 +278,15 @@ class KdbxBody extends KdbxNode {
 }
 
 class KdbxFormat {
-  static KdbxFile create(Credentials credentials, String name) {
+  static KdbxFile create(
+    Credentials credentials,
+    String name, {
+    String generator,
+  }) {
     final header = KdbxHeader.create();
     final meta = KdbxMeta.create(
       databaseName: name,
-      generator: 'AuthPass',
+      generator: generator,
     );
     final rootGroup = KdbxGroup.create(parent: null, name: name);
     final body = KdbxBody.create(meta, rootGroup);

lib/src/kdbx_meta.dart

@@ -8,11 +8,11 @@ import 'package:xml/xml.dart' as xml;
 class KdbxMeta extends KdbxNode {
   KdbxMeta.create({
     @required String databaseName,
-    String generator = 'kdbx.dart',
+    String generator,
   })  : customData = KdbxCustomData.create(),
         super.create('Meta') {
     this.databaseName.set(databaseName);
-    this.generator.set(generator);
+    this.generator.set(generator ?? 'kdbx.dart');
   }
 
   KdbxMeta.read(xml.XmlElement node)