anchor.diff:  
       services.zabbixServer.dbServer = mkOption {
         default = "localhost";
  +      type = types.str;
         description = ''
           Hostname or IP address of the database server.
           Use an empty string ("") to use peer authentication.
  
positive.code: 
      services.zabbixServer.dbPassword = mkOption {
        default = "";
        description = "Password used to connect to the database server.";
      };
  
    };
  
negative.code: 
      services.zabbixServer.enable = mkOption {
        default = false;
        type = types.bool;
        description = ''
          Whether to run the Zabbix server on this machine.
        '';
  