Description:

In Webhooks you can define your own avatar by using an image url or by choosing an emoji in the next field. This worked fine up to 0.71.1

Starting with 0.72.0, theese emojis aren't shown, neither in the webhook-setup-preview nor in the chat. This is regardless of using a new or an old webhook.

Steps to reproduce:

1. Go to Administration / Integrations -> new integration / Incoming Webhook integration
2. Check Preview, it should include the avatar of your rocket.cat user
3. Go to field "Emoji (optional)" and enter the example emoji (":ghost:"). Press to update the page.
4. Check Preview, the Avatar Picture just vanished.

Expected behavior:

The Avatar picture should change to the 👻 emoji

Server Setup Information:

• Version of Rocket.Chat Server: 0.72.0
• Operating System: linux
• Deployment Method: docker
• Number of Running Instances: 4
• DB Replicaset Oplog: Enabled
• NodeJS Version: v8.11.3
• MongoDB Version: 3.2.9