Remove obsolete const_fn feature gate on nightly

HybridEidolon · darfink · commit 3b6f17a8b51b · 2021-05-16T18:21:41.000+02:00
diff --git a/src/lib.rs b/src/lib.rs
@@ -1,7 +1,7 @@
 #![recursion_limit = "1024"]
 #![cfg_attr(
   feature = "nightly",
-  feature(const_fn, const_fn_trait_bound, unboxed_closures, abi_thiscall)
+  feature(const_fn_trait_bound, unboxed_closures, abi_thiscall)
 )]
 #![cfg_attr(
   all(feature = "nightly", test),
