[OpenSIPS-Devel] [OpenSIPS/opensips] f2d540: [cfg] fix bogus constraint on ':=' operator

[Bogdan Andrei IANCU]

  Branch: refs/heads/3.3
  Home:   https://github.com/OpenSIPS/opensips
  Commit: f2d540c8b38bee39cba9e6c586de9789fb51aca0
      https://github.com/OpenSIPS/opensips/commit/f2d540c8b38bee39cba9e6c586de9789fb51aca0
  Author: Bogdan-Andrei Iancu <bogdan at opensips.org>
  Date:   2023-11-28 (Tue, 28 Nov 2023)

  Changed paths:
    M cfg.y

  Log Message:
  -----------
  [cfg] fix bogus constraint on ':=' operator

It is actually implemented by BAVP also (not only AVPs), but the script does not allow its usage :(.
Removing the check is safe as all the other variables will treat the ':=' as '=' - they do not test the operator during "set", assuming '=' all the time.

(cherry picked from commit 5bab986c7c887a438e0cb007afa617ff6a5dcb4b)