[+] 修复手滑bug

修复了手滑写错的bug
增加了 example 的注释

example.php

@@ -1,7 +1,12 @@
 <?php
 Header("Content-type: text/plain");
+// Include Libvirt libraries
 include("libvirt/libvirt.php");
+// Instantiation Libvirt
 $Libvirt = new Libvirt();
+// Connect to 192.168.3.181:22 and set libvirt root at /data/libvirt/
 $Libvirt->setHost("192.168.3.181", 22, "/data/libvirt/");
+// Use the username 'root' and the password '123456' login to server.
 $Libvirt->connect("root", "123456");
-print_r($Libvirt->dumpxml("centos"));
+// Print the virtual machine centos's config file.
+echo $Libvirt->dumpxml("centos");