chore: upgrade rust-toolchain

Brooooooklyn · Brooooooklyn · commit 0f1320947ef6 · 2021-10-21T22:11:20.000+08:00
diff --git a/rust-toolchain b/rust-toolchain
@@ -1 +1 @@
-nightly-2021-09-08
+nightly-2021-10-21
