librustdoc: remove unneeded #[recursion_limit]

Author: yotamofek

src/librustdoc/lib.rs

@@ -18,7 +18,6 @@
 #![feature(test)]
 #![feature(type_alias_impl_trait)]
 #![feature(type_ascription)]
-#![recursion_limit = "256"]
 #![warn(rustc::internal)]
 
 extern crate thin_vec;