nixos: services: servarr: autobrr: fix websockets

I found some logs complaining about websockets before enabling this.

modules/nixos/services/servarr/autobrr.nix

@@ -40,6 +40,7 @@ in
     my.services.nginx.virtualHosts = {
       autobrr = {
         inherit (cfg) port;
+        websocketsLocations = [ "/api" ];
       };
     };