[OpenSIPS-Devel] [OpenSIPS/opensips] 3863f0: acc: prevent crash when drop_accounting() is used

[Razvan Crainea]

  Branch: refs/heads/2.4
  Home:   https://github.com/OpenSIPS/opensips
  Commit: 3863f03431d418d902457ed99948a7666fc9aa19
      https://github.com/OpenSIPS/opensips/commit/3863f03431d418d902457ed99948a7666fc9aa19
  Author: Razvan Crainea <razvan at opensips.org>
  Date:   2018-04-11 (Wed, 11 Apr 2018)

  Changed paths:
    M modules/acc/acc_logic.c
    M modules/acc/acc_logic.h

  Log Message:
  -----------
  acc: prevent crash when drop_accounting() is used

Reported by Tito Cumpen and Pete Kelly

Lots of thanks go to Pete Kelly for providing testing environment
and extended details about the issue

(cherry picked from commit 9de48658d35c62c5bcb888068d3e7978bd3aad6a)