fix screenshot bug in README

DIYgod · DIYgod · commit 1a03bfe9142d · 2015-11-15T14:29:01.000+08:00
diff --git a/README.md b/README.md
@@ -11,7 +11,7 @@ Wow, such a beautiful html5 music player
 [Demo](https://www.anotherhome.net/file/APlayer)
 
 Screenshot
-![image](http://github.com/DIYgod/APlayer/raw/master/screenshot.png)
+![image](https://github.com/DIYgod/APlayer/raw/master/screenshot.png)
 
 ## Install
 
