Fix link reference

Author: AndiDog

src/doc/unstable-book/src/language-features/compile-error.md

@@ -2,7 +2,7 @@
 
 The tracking issue for this feature is: [#40872]
 
-[#29599]: https://github.com/rust-lang/rust/issues/40872
+[#40872]: https://github.com/rust-lang/rust/issues/40872
 
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