Fix LocalStoreLayout using wrong type on message nonce field

Since nonce is an Object, passing a default value
of Possible-Object is valid under nonceOrElse,
creating a "valid" nested structure

This field makes sure nonce is passed a Possible
directly, skipping the Possible#of wrapping the
Object variant does

common/src/main/java/discord4j/common/store/impl/LocalStoreLayout.java

@@ -763,7 +763,7 @@ public Mono<MessageData> onMessageUpdate(int shardIndex, MessageUpdate dispatch)
                             .mentionChannels(edited.mentionChannels())
                             .attachments(edited.attachments())
                             .embeds(edited.embeds())
-                            .nonce(edited.nonceOrElse(m.nonce()))
+                            .nonce(edited.isNoncePresent() ? edited.nonce() : m.nonce())
                             .pinned(edited.pinnedOrElse(m.pinned()))
                             .webhookId(edited.isWebhookIdPresent() ? edited.webhookId() : m.webhookId())
                             .type(edited.typeOrElse(m.type()))