ffmpeg: 3.4.2 -> 3.4.3 (security)
ffmpeg: 3.4.2 -> 3.4.3 (security)

https://git.ffmpeg.org/gitweb/ffmpeg.git/blob/89355585366:/Changelog
/cc #42882: it certainly seems to fix some security issues,
but I'm not sure about mapping to particular CVE numbers;
perhaps it will appear on http://ffmpeg.org/security.html

NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs