message: Remove lack of mulithreading support from usage.md
diff: @@ -40,8 +40,7 @@ $ $cg_clif_dir/build/bin/cg_clif -Cllvm-args=mode=jit -Cprefer-dynamic my_crate.
  ```
  There is also an experimental lazy jit mode. In this mode functions are only compiled once they are
  -first called. It currently does not work with multi-threaded programs. When a not yet compiled
  -function is called from another thread than the main thread, you will get an ICE.
  +first called.
  ```bash
  $ $cg_clif_dir/build/cargo.sh lazy-jit
  