Rename marconi to zaqar

* projects.txt: The marconi project is now renamed to zaqar per
I8e587af588d9be0b5ebbab4b0f729b106a2ae537 so switching it here as
well to avoid breaking requirements proposals.

Change-Id: I53621558e5be365ea11849bbf8384c3416b6935a
(cherry picked from commit 0800f871e3b244707fd3fd3d258e40a9bc321edd)