bump rustc_version

Author: RalfJung

Cargo.lock

@@ -4560,9 +4560,9 @@ dependencies = [
 
 [[package]]
 name = "rustc_version"
-version = "0.4.0"
+version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bfa0f585226d2e68097d4f95d113b15b83a82e819ab25717ec0590d9584ef366"
+checksum = "cfcb3a22ef46e85b45de6ee7e79d063319ebb6594faafcf1c225ea92ab6e9b92"
 dependencies = [
  "semver",
 ]