make sysinfo provider a setting

src/sysinfo/interface.js

@@ -7,12 +7,13 @@
 // -------------------------------------------
 
 exports = module.exports = {
-    getPublicIp: getPublicIp
+    getServerIp: getServerIp
 };
 
 var assert = require('assert');
 
-function getPublicIp(callback) {
+function getServerIp(config, callback) {
+    assert.strictEqual(typeo config, 'object');
     assert.strictEqual(typeof callback, 'function');
 
     callback(new Error('not implemented'));