Fix TypeError: Cannot use 'in' operator to search for 'systemd' in 3000

Custom net.Server.prototype.listen method crashes when numeric port is passed to it.

May 18 03:44:14 buzby node[2085]: /srv/web-gui/node_app/node_modules/sd-daemon/index.js:61
May 18 03:44:14 buzby node[2085]: if (arg && 'systemd' in arg) {
May 18 03:44:14 buzby node[2085]: ^
May 18 03:44:14 buzby node[2085]: TypeError: Cannot use 'in' operator to search for 'systemd' in 3000
May 18 03:44:14 buzby node[2085]: at Server.net.Server.listen (/srv/web-gui/node_app/node_modules/sd-daemon/index...61:29)
May 18 03:44:14 buzby node[2085]: at Function.express.application.listen (/srv/web-gui/node_app/node_modules/expr...15:33)
May 18 03:44:14 buzby node[2085]: at /srv/web-gui/node_app/app.js:162:17
May 18 03:44:14 buzby node[2085]: at Statement.<anonymous> (/srv/web-gui/node_app/core/incidentManager.js:76:28)