Allow magnet URL scheme

[zeroware]

Description

I'm trying to send a link with the magnet URL scheme magnet:
The href attribute is removed when the link is displayed.

Steps to reproduce

• Post a link using matrix-js-sdk containing a magnet URL scheme in the href attribute
• The href attribute is removed

I expect the href attribute to be intact.

I may be wrong but I think we need to add the magnet scheme here :
https://github.com/matrix-org/matrix-react-sdk/blob/v0.9.7/src/HtmlUtils.js#L131

Version information

• web

For the web app:

• Browser: Firefox 54
• OS: Arch Linux
• URL: riot.im/app

[zeroware]

Just made a pull request to fix it : matrix-org/matrix-react-sdk#1301

[t3chguy]

Closing in favour of #15018