[OpenSIPS-Devel] [OpenSIPS/opensips] 706e79: launch() statement: Fix an AVP list management bug

[Liviu Chircu]

  Branch: refs/heads/3.0
  Home:   https://github.com/OpenSIPS/opensips
  Commit: 706e798d5ecc8109e335c4120f5d7f8fcf183c9e
      https://github.com/OpenSIPS/opensips/commit/706e798d5ecc8109e335c4120f5d7f8fcf183c9e
  Author: Liviu Chircu <liviu at opensips.org>
  Date:   2019-11-11 (Mon, 11 Nov 2019)

  Changed paths:
    M async.c

  Log Message:
  -----------
  launch() statement:  Fix an AVP list management bug

Whenever a launch() operation gets executed inline (thanks to some
favorable conditions), two things must happen:

    * no AVP from the message execution context should leak into the
      report route execution context

    * the AVPs from the message execution context must be restored
      after running the report route.  They _must not_ be destroyed,
      as message processing will continue afterwards!

Many thanks to Alexey Vasilyev for some valuable troubleshooting info
Fixes #1580

(cherry picked from commit 4a639db5b110de5da03e23607f0d74549a0e6087)