sysinfo: add noop provider

src/sysinfo.js

@@ -18,6 +18,7 @@ function api(provider) {
     assert.strictEqual(typeof provider, 'string');
 
     switch (provider) {
+    case 'noop': return require('./sysinfo/noop.js');
     case 'fixed': return require('./sysinfo/fixed.js');
     case 'network-interface': return require('./sysinfo/network-interface.js');
     default: return require('./sysinfo/generic.js');
@@ -33,10 +34,8 @@ async function getServerIPv4() {
 // returns RFC 5952 formatted address (https://datatracker.ietf.org/doc/html/rfc5952)
 async function getServerIPv6() {
     const config = await settings.getIPv6Config();
-
-    if (config.provider === 'noop') return null;
-
     const result = await api(config.provider).getServerIPv6(config);
+    if (!result) return null;
     return ipaddr.parse(result).toRFC5952String();
 }