[Firefox] Urls without protocol specified can't be opened in browser

Checklist

• I am reporting an issue in existing functionality that does not work as intended
• I've searched for existing GitHub issues

Description

Using Firefox as default browser for opening links. In Telegram when I click on url that doesn't have a protocol in it (e.g. example.com) it opens a Firefox with a blank page.

Expected Behavior

Telegram should provide a protocol in the url so that Firefox can open it. So that when I click on url example.com, Telegram passes it as http://example.com to Firefox.

Actual Behavior

When I click on url without protocol (e.g. example.com) it opens a Firefox with a blank page.

Steps to Reproduce

1. Open Telegram.
2. Go to Settings and set Firefox as default browser for opening links.
3. Go to "Saved messages".
4. Send yourself a message: example.com.
5. Click on a link in sent message.
6. Observe Firefox opening a new blank tab without url.

Environment

Device: iPhone 7

iOS version: 13.4.1

App version: 6.1.2

Start by reproducing the issue on an iPhone running iOS 13.4.1 with Firefox set as the default browser, using a protocol-less URL such as example.com from Saved Messages. Trace the link-opening path and verify that the completed change opens the URL with a protocol instead of a blank Firefox tab.