rspamd: 1.6.5 -> 1.6.6

Semi-automatic update. These checks were performed:

- built on NixOS
- ran `/nix/store/9amnrkqxnjyf4fj463dglp0cvkf5wh52-rspamd-1.6.6/bin/rspamd -h` got 0 exit code
- ran `/nix/store/9amnrkqxnjyf4fj463dglp0cvkf5wh52-rspamd-1.6.6/bin/rspamd --help` got 0 exit code
- ran `/nix/store/9amnrkqxnjyf4fj463dglp0cvkf5wh52-rspamd-1.6.6/bin/rspamd -v` and found version 1.6.6
- ran `/nix/store/9amnrkqxnjyf4fj463dglp0cvkf5wh52-rspamd-1.6.6/bin/rspamd --version` and found version 1.6.6
- ran `/nix/store/9amnrkqxnjyf4fj463dglp0cvkf5wh52-rspamd-1.6.6/bin/rspamd -h` and found version 1.6.6
- ran `/nix/store/9amnrkqxnjyf4fj463dglp0cvkf5wh52-rspamd-1.6.6/bin/rspamd --help` and found version 1.6.6
- ran `/nix/store/9amnrkqxnjyf4fj463dglp0cvkf5wh52-rspamd-1.6.6/bin/rspamc --help` got 0 exit code
- ran `/nix/store/9amnrkqxnjyf4fj463dglp0cvkf5wh52-rspamd-1.6.6/bin/rspamc help` got 0 exit code
- ran `/nix/store/9amnrkqxnjyf4fj463dglp0cvkf5wh52-rspamd-1.6.6/bin/rspamc --help` and found version 1.6.6
- ran `/nix/store/9amnrkqxnjyf4fj463dglp0cvkf5wh52-rspamd-1.6.6/bin/rspamadm -h` got 0 exit code
- ran `/nix/store/9amnrkqxnjyf4fj463dglp0cvkf5wh52-rspamd-1.6.6/bin/rspamadm --help` got 0 exit code
- ran `/nix/store/9amnrkqxnjyf4fj463dglp0cvkf5wh52-rspamd-1.6.6/bin/rspamadm help` got 0 exit code
- ran `/nix/store/9amnrkqxnjyf4fj463dglp0cvkf5wh52-rspamd-1.6.6/bin/rspamadm -v` and found version 1.6.6
- ran `/nix/store/9amnrkqxnjyf4fj463dglp0cvkf5wh52-rspamd-1.6.6/bin/rspamadm --version` and found version 1.6.6
- ran `/nix/store/9amnrkqxnjyf4fj463dglp0cvkf5wh52-rspamd-1.6.6/bin/rspamadm -h` and found version 1.6.6
- ran `/nix/store/9amnrkqxnjyf4fj463dglp0cvkf5wh52-rspamd-1.6.6/bin/rspamadm --help` and found version 1.6.6
- ran `/nix/store/9amnrkqxnjyf4fj463dglp0cvkf5wh52-rspamd-1.6.6/bin/rspamadm help` and found version 1.6.6
- found 1.6.6 with grep in /nix/store/9amnrkqxnjyf4fj463dglp0cvkf5wh52-rspamd-1.6.6
- found 1.6.6 in filename of file in /nix/store/9amnrkqxnjyf4fj463dglp0cvkf5wh52-rspamd-1.6.6

cc "@avnik @fpletz"