Merge pull request #1222 from rust-lang/dependabot/cargo/once_cell-1.7.2

Cargo.lock

@@ -1029,9 +1029,9 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.7.0"
+version = "1.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "10acf907b94fc1b1a152d08ef97e7759650268cf986bf127f387e602b02c7e5a"
+checksum = "af8b08b04175473088b46763e51ee54da5f9a164bc162f615b91bc179dbf15a3"
 
 [[package]]
 name = "opaque-debug"