Bug 1621371 - Update servo-fontconfig-sys to avoid intermittent build errors. r=kvark
Bug 1621371 - Update servo-fontconfig-sys to avoid intermittent build errors. r=kvark

The lack of https://github.com/servo/libfontconfig/pull/42 in 4.0.4
broke rust CI

Differential Revision: https://phabricator.services.mozilla.com/D66275

[ghsync] From https://hg.mozilla.org/mozilla-central/rev/399aeed6f2c4f1e4300b3a11ee740464e0e0d5c3

servo/webrender,servo/webrender,servo/webrender,servo/webrender,servo/webrender,servo/webrender