Increase breaker limit in NettyHttpRequestSizeLimitIT

With the previous breaker limit spurious failures on transport level
can happen in the test. With the new limit we ensure that the breaker
breaks due to a too large HTTP request instead.

core/src/test/java/org/elasticsearch/http/netty/NettyHttpRequestSizeLimitIT.java

@@ -42,7 +42,7 @@ import static org.hamcrest.Matchers.hasSize;
  */
 @ClusterScope(scope = Scope.TEST, numDataNodes = 1)
 public class NettyHttpRequestSizeLimitIT extends ESIntegTestCase {
-    private static final ByteSizeValue LIMIT = new ByteSizeValue(1, ByteSizeUnit.KB);
+    private static final ByteSizeValue LIMIT = new ByteSizeValue(2, ByteSizeUnit.KB);
 
     @Override
     protected Settings nodeSettings(int nodeOrdinal) {