polling-xhr: always close body

src/main/java/io/socket/engineio/client/transports/PollingXHR.java

@@ -20,6 +20,7 @@ import okhttp3.MediaType;
 import okhttp3.OkHttpClient;
 import okhttp3.RequestBody;
 import okhttp3.Response;
+import okhttp3.ResponseBody;
 
 public class PollingXHR extends Polling {
 
@@ -196,11 +197,15 @@ public class PollingXHR extends Polling {
                     self.response = response;
                     self.onResponseHeaders(response.headers().toMultimap());
 
+                    try {
                         if (response.isSuccessful()) {
                             self.onLoad();
                         } else {
                             self.onError(new IOException(Integer.toString(response.code())));
                         }
+                    } finally {
+                        response.close();
+                    }
                 }
             });
         }