rustbook: no-longer-used feature gate

tshepang · tshepang · commit ac3a39015c7f · 2015-02-18T23:27:32.000+02:00
diff --git a/src/rustbook/main.rs b/src/rustbook/main.rs
@@ -12,7 +12,6 @@
 #![feature(collections)]
 #![feature(core)]
 #![feature(old_io)]
-#![feature(os)]
 #![feature(env)]
 #![feature(old_path)]
 #![feature(rustdoc)]
