add api host global for autoload

Author: longbai

qiniu/conf.php

@@ -4,6 +4,8 @@
 global $QINIU_UP_HOST;
 global $QINIU_RS_HOST;
 global $QINIU_RSF_HOST;
+global $QINIU_API_HOST;
+global $QINIU_IOVIP_HOST;
 
 global $QINIU_ACCESS_KEY;
 global $QINIU_SECRET_KEY;