Update Chat Server Link

[naphelps]

The Matrix chat server used by the Linux Foundation is getting retired. It has been replaced with a Zulip server.

Old:

.github/profile/README.md

Line 31 in a6fbaa1

- [Chat Server](https://chat.lfx.linuxfoundation.org/ )

New:

 - [Chat Server](https://linuxfoundation.zulipchat.com/#narrow/channel/527924-open-horizon)

[ayan-ali-khan]

/assign

[joewxboy]

@ayan-ali-khan If you want to link directly to the Open Horizon channel on the server, the link is #open-horizon

[ayan-ali-khan]

@naphelps changes have been made. Chat server link has been updated and pull request is made. Kindly check the changes and accept it.