fix bug https://ssl.izenesoft.cn/bug/show_bug.cgi?id=81, if mysql server is restarted, it's revised to reconnect mysql server.
fix bug https://ssl.izenesoft.cn/bug/show_bug.cgi?id=81,
if mysql server is restarted, it's revised to reconnect mysql server.

pombredanne/sf1r-lite,izenecloud/sf1r-ad-delivery,izenecloud/sf1r-lite,pombredanne/sf1r-lite,izenecloud/sf1r-lite,izenecloud/sf1r-lite,izenecloud/sf1r-lite,pombredanne/sf1r-lite,pombredanne/sf1r-lite,izenecloud/sf1r-ad-delivery,izenecloud/sf1r-ad-delivery,pombredanne/sf1r-lite,izenecloud/sf1r-ad-delivery,izenecloud/sf1r-lite,izenecloud/sf1r-ad-delivery