fix wrong URL

Author: mr-c

README.rst

@@ -152,7 +152,7 @@ Run `cwltool` just as you normally would, but with the new option, e.g. from the
 
 .. code:: bash
 
-  cwltool --user-space-docker-cmd=udocker https://raw.githubusercontent.com/common-workflow-language/common-workflow-language/main/v1.0/v1.0/test-cwl-out2.cwl https://github.com/common-workflow-language/common-workflow-language/blob/main/v1.0/v1.0/empty.json
+  cwltool --user-space-docker-cmd=udocker https://raw.githubusercontent.com/common-workflow-language/common-workflow-language/main/v1.0/v1.0/test-cwl-out2.cwl https://github.com/common-workflow-language/common-workflow-language/raw/main/v1.0/v1.0/empty.json
 
 ``cwltool`` can also use `Singularity <https://github.com/hpcng/singularity/releases/>`_ version 2.6.1
 or later as a Docker container runtime.