nixos/tts: fix error messages read before text

with a config like this :

```
services.tts = {
  servers = {
    english = {
      enable = true;
      port = 5300;
      model = "tts_models/en/ljspeech/vits"
    };
  };
};
```

You the WAVs tts creates contain an error message which will be read to
you before the text you typed in will be read to you.
This patch fixes that.

1 files changed, 1 insertions, 0 deletions

diff --git a/nixos/modules/services/audio/tts.nix b/nixos/modules/services/audio/tts.nix
index 1a355c8ee39f..0d93224ec030 100644
--- a/nixos/modules/services/audio/tts.nix
+++ b/nixos/modules/services/audio/tts.nix
@@ -134,6 +134,7 @@ in
           ProtectProc = "invisible";
           ProcSubset = "pid";
           RestrictAddressFamilies = [
+            "AF_UNIX"
             "AF_INET"
             "AF_INET6"
           ];