Avoid downgrading to Stable despite RUSTC_BOOTSTRAP

error[E0658]: platform intrinsics are experimental and possibly buggy
  --> src/simd_llvm.rs:13:8
   |
13 | extern "platform-intrinsic" {
   |        ^^^^^^^^^^^^^^^^^^^^
   |
   = note: see issue #27731 <https://github.com/rust-lang/rust/issues/27731> for more information
   = help: add `#![feature(platform_intrinsics)]` to the crate attributes to enable

--- cargo-crates/vek-0.16.1/build.rs.orig	1970-01-01 00:00:00 UTC
+++ cargo-crates/vek-0.16.1/build.rs
@@ -4,19 +4,6 @@ fn main() {
 fn main() {
     assert!(version().unwrap().major >= 1);
 
-    match version_meta().unwrap().channel {
-        Channel::Stable => {
-            println!("cargo:rustc-cfg=stable");
-        }
-        Channel::Beta => {
-            println!("cargo:rustc-cfg=beta");
-        }
-        Channel::Nightly => {
-            println!("cargo:rustc-cfg=nightly");
-        }
-        Channel::Dev => {
-            println!("cargo:rustc-cfg=dev");
-        }
-    }
+    println!("cargo:rustc-cfg=nightly");
 }
 
