Re-adds removed return statement

Signed-off-by: Darshit Chanpura <[email protected]>

src/main/java/org/opensearch/security/auth/BackendRegistry.java

@@ -295,7 +295,7 @@ public boolean authenticate(final SecurityRequestChannel request) {
                         }
                         notifyIpAuthFailureListeners(request, authCredentials);
                         request.queueForSending(restResponse.get());
-
+                        return false;
                     }
                 } else {
                     // no reRequest possible