Fix deadlock in DirectDruidClient

server/src/main/java/io/druid/client/DirectDruidClient.java

@@ -214,9 +214,7 @@ public class DirectDruidClient<T> implements QueryRunner<T>
                     @Override
                     public InputStream nextElement()
                     {
-                      synchronized (done) {
                       try {
-                          // Ensures more elements are expected via `done`
                         return queue.take();
                       }
                       catch (InterruptedException e) {
@@ -225,7 +223,6 @@ public class DirectDruidClient<T> implements QueryRunner<T>
                       }
                     }
                   }
-                  }
               )
           );
         }