RestForwarder: Replace lambda with method reference

Change-Id: I6488c8558fcca3b144feb886a41f7759efb42ebe
diff --git a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/RestForwarder.java b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/RestForwarder.java
index 32c56bf..15c3f63 100644
--- a/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/RestForwarder.java
+++ b/src/main/java/com/ericsson/gerrit/plugins/highavailability/forwarder/rest/RestForwarder.java
@@ -133,7 +133,7 @@
             .get()
             .stream()
             .map(peer -> createRequest(method, peer, action, endpoint, id, payload))
-            .map(request -> CompletableFuture.supplyAsync(() -> request.execute()))
+            .map(request -> CompletableFuture.supplyAsync(request::execute))
             .collect(Collectors.toList());
     CompletableFuture.allOf(futures.toArray(new CompletableFuture[0])).join();
     return futures.stream().allMatch(CompletableFuture::join);