Restore RuStore support through replace URL of API.

If the application is published as an AAB,
then the old one produced an unusable file (one of split files).
The new one provide a monolithic file.

lib/app_sources/rustore.dart

@@ -80,20 +80,20 @@ class RuStore extends AppSource {
     }
 
     Response res1 = await sourceRequest(
-      'https://backapi.rustore.ru/applicationData/download-link',
+      'https://backapi.rustore.ru/applicationData/v2/download-link',
       additionalSettings,
       followRedirects: false,
       postBody: {"appId": appDetails['appId'], "firstInstall": true},
     );
     var downloadDetails = (await decodeJsonBody(res1.bodyBytes))['body'];
-    if (res1.statusCode != 200 || downloadDetails['apkUrl'] == null) {
+    if (res1.statusCode != 200 || downloadDetails['downloadUrls'][0]['url'] == null) {
       throw NoAPKError();
     }
 
     return APKDetails(
       version,
       getApkUrlsFromUrls([
-        (downloadDetails['apkUrl'] as String).replaceAll(
+        (downloadDetails['downloadUrls'][0]['url'] as String).replaceAll(
           RegExp('\\.zip\$'),
           '.apk',
         ),