DOC: Fixed formatting in README_SETUP.md

README_SETUP.md

@@ -200,7 +200,7 @@ Stand-alone documentation is built using Sphinx: `make doc`
   - Alternative, if javasphinx fails because python3-sphinx is too recent:
     (`l_` not found):
 
-    ```sh
+```sh
 git clone git@github.com:simgrid/javasphinx.git
 cd javasphinx
 git checkout 659209069603a