REST: No strict warning testing for head body test

Our tests that HEAD requests don't have a body was hitting a warning.
For now we'll run that test without "strict" warnings mode enabled.

modules/transport-netty4/src/test/java/org/elasticsearch/rest/Netty4HeadBodyIsEmptyIT.java

@@ -38,7 +38,6 @@
 import static org.hamcrest.Matchers.greaterThan;
 
 public class Netty4HeadBodyIsEmptyIT extends ESRestTestCase {
-
     public void testHeadRoot() throws IOException {
         headTestCase("/", emptyMap(), greaterThan(0));
         headTestCase("/", singletonMap("pretty", ""), greaterThan(0));
@@ -75,6 +74,12 @@ public void testIndexExists() throws IOException {
         headTestCase("/test", singletonMap("pretty", "true"), greaterThan(0));
     }
 
+    @Override
+    protected boolean getStrictDeprecationMode() {
+        // Remove this override when we remove the reference to types below
+        return false;
+    }
+
     public void testTypeExists() throws IOException {
         createTestDoc();
         headTestCase("/test/_mapping/test", emptyMap(), greaterThan(0));