Correct documentation hyperlink for environment-markers

Previous hyperlink was redirected to root of the new documentation
location which did not contain the right information.

New link points directly to the right location.

Change-Id: I3c83553a50036eadec74e7a00f3b312a7e5afa11

pbr/util.py

@@ -459,7 +459,7 @@ def setup_cfg_to_setup_kwargs(config, script_args=()):
                             "Marker evaluation failed, see the following "
                             "error.  For more information see: "
                             "http://docs.openstack.org/"
-                            "developer/pbr/compatibility.html#evaluate-marker"
+                            "pbr/latest/user/using.html#environment-markers"
                         )
                         raise
             else: