Remove troublesome fonts from font stack

See Ibb16c93ef7f0c7efd5ba963d01e6dc5db61fdc87, especially
https://gerrit.wikimedia.org/r/#/c/124387/1/skins/vector/variables.less

Change-Id: I555862a3c64cd08f5755b9ba1d63450a5186dd73
Merge "Remove troublesome fonts from font stack"