Remove mention of removal of static mut

Author: rylev

posts/inside-rust/2021-03-03-planning-rust-2021.md

@@ -42,7 +42,7 @@ In Rust 2021 this new resolver will become the default, but older editions can s
 
 ### Other 
 
-Other proposed changes include [unifying how `panic` in `std` and `core` work](https://github.com/rust-lang/rust/issues/80162), upgrading several lints from [warnings to errors](https://github.com/rust-lang/rust/issues/80165), and [removing `static mut`](https://github.com/rust-lang/rust/issues/53639). 
+Other proposed changes include [unifying how `panic` in `std` and `core` work](https://github.com/rust-lang/rust/issues/80162) and upgrading several lints from [warnings to errors](https://github.com/rust-lang/rust/issues/80165).
 
 You can find a full list of features that are under consideration [here](https://docs.google.com/spreadsheets/d/1chZ2SL9T444nvU9al1kQ7TJMwC3IVQQV2xIv1HWGQ_k/edit?usp=sharing).