irssi: 1.2.2 -> 1.2.3

[LeSuisse]

Motivation for this change

Release notes:
https://github.com/irssi/irssi/releases/tag/1.2.3

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

Result of nixpkgs-review run on x86_64-linux 1

2 packages built:

• irssi
• irssi_fish

[fabaff]

Result of nixpkgs-review pr 119173 run on x86_64-linux 1

2 packages built:

• irssi
• irssi_fish

[fabaff]

• package built (see irssi: 1.2.2 -> 1.2.3 #119173 (comment))
• all depending packages build
• tested on x86_64

...ew/pr-119173]$ ./results/irssi/bin/irssi -v
irssi 1.2.3 (20210409 0011)

Change looks good to me. TUI works.