remove recursion limit (#3348)

According to the
[doc](https://doc.rust-lang.org/reference/attributes/limits.html), the
default is 128, so no point to specify limit with 128

Co-authored-by: Bastian Köcher <git@kchr.de>

substrate/client/executor/src/lib.rs

@@ -29,7 +29,6 @@
 //! wasm engine used, instance cache.
 
 #![warn(missing_docs)]
-#![recursion_limit = "128"]
 
 #[macro_use]
 mod executor;