[Client] Compatibility header: use text/plain

Author: picandocodigo

api-spec-testing/wipe_cluster_8.rb

@@ -134,7 +134,7 @@ def wipe_rollup_jobs(client)
         def wait_for_pending_rollup_tasks(client)
           filter = 'xpack/rollup/job'
           loop do
-            results = client.cat.tasks(detailed: true)
+            results = client.cat.tasks(detailed: true).split("\n")
             count = 0
 
             time = Time.now.to_i

elasticsearch-transport/lib/elasticsearch/transport/client.rb

@@ -211,7 +211,7 @@ def set_compatibility_header
 
         add_header(
           {
-            'Accept' => 'application/vnd.elasticsearch+json;compatible-with=7',
+            'Accept' => 'application/vnd.elasticsearch+json; compatible-with=7',
             'Content-Type' => 'application/vnd.elasticsearch+json; compatible-with=7'
           }
         )

elasticsearch-transport/spec/elasticsearch/transport/client_spec.rb

@@ -1432,10 +1432,7 @@
         headers = client.transport.connections.first.connection.headers
 
         expect(headers['Content-Type']).to eq('application/vnd.elasticsearch+json; compatible-with=7')
-        expect(headers['Accept']).to eq('application/vnd.elasticsearch+json;compatible-with=7')
-
-        response = client.perform_request('GET', '/')
-        expect(response.headers['content-type']).to eq('application/json; charset=UTF-8')
+        expect(headers['Accept']).to eq('application/vnd.elasticsearch+json; compatible-with=7')
 
         ENV.delete('ELASTIC_CLIENT_APIVERSIONING')
       end

elasticsearch-xpack/spec/xpack/rest_api_yaml_spec.rb

@@ -65,9 +65,6 @@
                 ADMIN_CLIENT.xpack.watcher.delete_watch(id: 'my_watch')
               rescue Elasticsearch::Transport::Transport::Errors::NotFound
               end
-              # todo: remove these two lines when Dimitris' PR is merged
-              ADMIN_CLIENT.cluster.put_settings(body: { transient: { 'xpack.ml.max_model_memory_limit' => nil } })
-              ADMIN_CLIENT.cluster.put_settings(body: { persistent: { 'xpack.ml.max_model_memory_limit' => nil } })
               test_file.setup
             end