Fix typo in comment in IndexShardTestCase

This commit fixes a silly typo in IndexShardTestCase.java.

test/framework/src/main/java/org/elasticsearch/index/shard/IndexShardTestCase.java

@@ -239,7 +239,7 @@ public abstract class IndexShardTestCase extends ESTestCase {
                                   @Nullable EngineFactory engineFactory,
                                   IndexingOperationListener... listeners)
         throws IOException {
-        // add node id as name to settings for popper logging
+        // add node id as name to settings for proper logging
         final ShardId shardId = routing.shardId();
         final NodeEnvironment.NodePath nodePath = new NodeEnvironment.NodePath(createTempDir());
         ShardPath shardPath = new ShardPath(false, nodePath.resolve(shardId), nodePath.resolve(shardId), shardId);