[OpenSIPS-Devel] [OpenSIPS/opensips] 5d5e95: Fix docs, removed old rule_attrs_avp modparam

[Bogdan Andrei IANCU]

  Branch: refs/heads/master
  Home:   https://github.com/OpenSIPS/opensips
  Commit: 5d5e956fb53e4f4ac8826b23b0f0a1600b7b14df
      https://github.com/OpenSIPS/opensips/commit/5d5e956fb53e4f4ac8826b23b0f0a1600b7b14df
  Author: Bogdan-Andrei Iancu <bogdan at opensips.org>
  Date:   2021-06-04 (Fri, 04 Jun 2021)

  Changed paths:
    M modules/drouting/doc/drouting_admin.xml

  Log Message:
  -----------
  Fix docs, removed old rule_attrs_avp modparam

This was replaced for a long time by the `rule_attrs_pvar` param of `do_routing()`
Reported by @MosinAnton
Closes #2537

(cherry picked from commit 8ffc647af7d28d9be08c4805ad1fd0b7aa852966)