Simplify unnecessary flatMap in demo

Author: emlun

webauthn-server-demo/src/main/java/demo/webauthn/InMemoryRegistrationStorage.java

@@ -94,15 +94,14 @@ public Optional<RegisteredCredential> lookup(ByteArray credentialId, ByteArray u
         credentialId,
         userHandle,
         registrationMaybe);
-    return registrationMaybe.flatMap(
+    return registrationMaybe.map(
         registration ->
-            Optional.of(
-                RegisteredCredential.builder()
-                    .credentialId(registration.getCredential().getCredentialId())
-                    .userHandle(registration.getUserIdentity().getId())
-                    .publicKeyCose(registration.getCredential().getPublicKeyCose())
-                    .signatureCount(registration.getCredential().getSignatureCount())
-                    .build()));
+            RegisteredCredential.builder()
+                .credentialId(registration.getCredential().getCredentialId())
+                .userHandle(registration.getUserIdentity().getId())
+                .publicKeyCose(registration.getCredential().getPublicKeyCose())
+                .signatureCount(registration.getCredential().getSignatureCount())
+                .build());
   }
 
   @Override