Fatal error: Uncaught exception Error with message Call to undefined function Contao\Database\mysql_connect() thrown in system/modules/core/library/Contao/Database/Mysql.php on line 64

#0 system/modules/core/library/Contao/Database.php(77): Contao\Database\Mysql->connect()
#1 system/modules/core/library/Contao/Database.php(160): Contao\Database->__construct()
#2 [internal function]: Contao\Database::getInstance()
#3 system/modules/core/library/Contao/System.php(110): call_user_func()
#4 system/modules/core/library/Contao/User.php(89): Contao\System->import()
#5 system/modules/core/classes/FrontendUser.php(79): Contao\User->__construct()
#6 system/modules/core/library/Contao/User.php(151): Contao\FrontendUser->__construct()
#7 [internal function]: Contao\User::getInstance()
#8 system/modules/core/library/Contao/System.php(110): call_user_func()
#9 index.php(41): Contao\System->import()
#10 index.php(414): Index->__construct()
#11 {main}