corpus map data json cahe aware of language

sites/all/modules/figli/edlp_corpus/src/Controller/CorpusController.php

@@ -126,14 +126,15 @@ class CorpusController extends ControllerBase {
       'count' => count($nodes),
       'nodes' => $nodes_data,
       'entrees' => $entrees,
-      'langcode' => $current_langcode,
+      'language' => $current_langcode,
     );
 
     // https://spinningcode.org/2017/05/cached-json-responses-in-drupal-8/
     // cache is invalidated in edlp_corpus.module by tags
     $data['#cache'] = [
       'max-age' => \Drupal\Core\Cache\Cache::PERMANENT,
-      'tags' => ['rebuild-corpus-cache']
+      'tags' => ['rebuild-corpus-cache'],
+      'contexts' => ['languages:language_content'],
     ];
 
     // $response = new JsonResponse();