Live Update Error

I've just purchased a live update ID hoping to easily update from 3.3.6 to 3.5.6, but when I try to run the live update it just throws up an error. I've always done manual updates in the past, but thought I'd make things easier on myself this time. Maybe I'm doing something wrong, but when I click run update button this comes up:

Deprecated notice: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in system/modules/core/library/Contao/Database/Mysql.php on line 58

#0 [internal function]: __error(8192, 'mysql_connect()...', '/home3/advocac1...', 58, Array)
#1 system/modules/core/library/Contao/Database/Mysql.php(58): mysql_connect('localhost:3306', 'advocac1_contao', 'dfgdg345y3')
#2 system/modules/core/library/Contao/Database.php(77): Contao\Database\Mysql->connect()
#3 system/modules/core/library/Contao/Database.php(161): Contao\Database->__construct(Array)
#4 [internal function]: Contao\Database::getInstance()
#5 system/modules/core/library/Contao/System.php(122): call_user_func(Array)
#6 system/modules/core/library/Contao/User.php(89): Contao\System->import('Database')
#7 system/modules/core/classes/BackendUser.php(103): Contao\User->__construct()
#8 system/modules/core/library/Contao/User.php(151): Contao\BackendUser->__construct()
#9 [internal function]: Contao\User::getInstance()
#10 system/modules/core/library/Contao/System.php(122): call_user_func(Array)
#11 contao/main.php(56): Contao\System->import('BackendUser', 'User')
#12 contao/main.php(292): Main->__construct()
#13 {main}

Any suggestions?
Thanks.

Hi, you may want to run the Contao Install Tool and change the database driver to "MySQLi".

Thanks for the pointer, I was able to get everything fixed, updated, and resolved all the errors the site was having.