doc: add /rest/data/user/roles ignores query options

So you can add ?@verbose=2 etc. for compatibility with a real
collection endpoint, but it ignores them.

Author: rouilj

doc/rest.txt

@@ -1120,9 +1120,9 @@ authorized error.  The output from this endpoint looks like::
 to mimic a class collection.
 
 Unlike a real class collection endpoint, ``@total_size`` is not
-returned. Also it does not support any query options like: filtering,
-`@sort`, `@group`, `@verbose` etc. Note that the ``id`` property is
-not numeric.
+returned. Also it does not support and ignores any query options like:
+filtering, `@sort`, `@group`, `@verbose` etc. Note that the ``id``
+property is not numeric.
 
 This endpoint was introduced in release 2.4.0 to support a roles
 select/dropdown in the web component classhelper. This lets the web