Auto merge of servo#16953 - servo:jdm-patch-1, r=SimonSapin

Avoid the cert revocation check in Cargo.

Per rust-lang/cargo#4072 Cargo on Windows is having trouble due to a letsencrypt outage. Our Appveyor CI is busted, as is our Windows builder for any PR that needs to upgrade a package from crates.io.

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Author: bors-servo

.cargo/config

@@ -0,0 +1 @@
+check-revoke = false