Reword bootstrap comment

Author: dtolnay

build.rs

@@ -44,10 +44,13 @@ fn main() {
 
 fn compile_probe() -> Option<ExitStatus> {
     if env::var_os("RUSTC_STAGE").is_some() {
-        // We are running inside rustc bootstrap. This is a highly non-standard environment with
-        // issues such as <https://github.com/rust-lang/cargo/issues/11138> and
-        // <https://github.com/rust-lang/rust/issues/114839>. Let's just not use nightly features
-        // here.
+        // We are running inside rustc bootstrap. This is a highly non-standard
+        // environment with issues such as:
+        //
+        //     https://github.com/rust-lang/cargo/issues/11138
+        //     https://github.com/rust-lang/rust/issues/114839
+        //
+        // Let's just not use nightly features here.
         return None;
     }