Bump version to 0.6.8

Author: crazywhalecc

src/OneBot/global_defines.php

@@ -13,7 +13,7 @@
 use ZM\Logger\ConsoleLogger;
 
 const ONEBOT_VERSION = '12';
-const ONEBOT_LIBOB_VERSION = '0.6.7';
+const ONEBOT_LIBOB_VERSION = '0.6.8';
 
 const ONEBOT_JSON = 1;
 const ONEBOT_MSGPACK = 2;