double Url encoding from webhook with whitespace replacement

Description:

I use the webhook from Rocket.Chat to send messages to a Rocket.Chat channel.

I want to post a message, which contains a link.
Part of the message content ist [LinkName](https://myurl.org/some space/index.html) interpreted by Rocket.Chat as markdown.

The problem is, that the Url contains a whitespace.
In the past, it was possible to encode the url and send it to the Rocket.Chat in the way, that the markdown looked like: LinkName

It looks like this is no longer possible. As I understand the Url ist encoded again from Rocket.Chat. The result I get, when I use the encoded URL is: LinkName
because the % sign is encoded again by Rocket.Chat.

When I do not encode the url by myself, Rocket.Chat does not encode the Url by itself. So sending [LinkName](https://myurl.org/some space/index.html) will still result in [LinkName](https://myurl.org/some space/index.html), means no encoding happened.

Steps to reproduce:

1. Create a message with an Link in markdown typeURL contain
2. Send the message through the webhook to an Rocket.Chat channel
3. Check the send message in the channel. The containing whitespace is not correct encoded

Expected behavior:

Rocket.Chat encodes the url in the link part of the markdown and replaces the whitespace with an %20 or the url is not encoded by Rocket.Chat and does not replace the % sign with %25

Actual behavior:

If a whitespace is used in the url-part of the markdown link, the whitespace is not encoded by Rocket.Chat webhook. If the whitespace is encoded before by the sender, the Rocket.Chat webhook replaces the % sign again with %25

Server Setup Information:

• Version of Rocket.Chat Server: 3.9.7
• Operating System: linux
• Deployment Method: native
• Number of Running Instances: 1
• DB Replicaset Oplog: activated
• NodeJS Version: v12.18.4
• MongoDB Version: 3.6.14

Client Setup Information

• Desktop App or Browser Version: Desktop App
• Operating System: Windows

Additional context

Relevant logs:

Start by reproducing the webhook message with a Markdown link containing a space, then trace the webhook's Markdown URL handling. Compare pre-encoded and unencoded URLs; done means spaces are encoded once and existing percent escapes are not double-encoded.