Warning: Undefined property: wpdb::$use_mysqli in /usr/www/users/smiczajxip/wp-includes/class-wpdb.php on line 768

Fatal error: Uncaught Error: Call to undefined function mysql_get_server_info() in /usr/www/users/smiczajxip/wp-content/plugins/health-check/includes/class-health-check-site-status.php:52
Stack trace:
#0 /usr/www/users/smiczajxip/wp-content/plugins/health-check/includes/class-health-check-site-status.php(22): Health_Check_Site_Status->prepare_sql_data()
#1 /usr/www/users/smiczajxip/wp-content/plugins/health-check/includes/class-health-check-site-status.php(18): Health_Check_Site_Status->init()
#2 /usr/www/users/smiczajxip/wp-content/plugins/health-check/includes/class-health-check-site-status.php(2039): Health_Check_Site_Status->__construct()
#3 /usr/www/users/smiczajxip/wp-content/plugins/health-check/health-check.php(65): require_once('/usr/www/users/...')
#4 /usr/www/users/smiczajxip/wp-settings.php(473): include_once('/usr/www/users/...')
#5 /usr/www/users/smiczajxip/wp-config.php(97): require_once('/usr/www/users/...')
#6 /usr/www/users/smiczajxip/wp-load.php(50): require_once('/usr/www/users/...')
#7 /usr/www/users/smiczajxip/wp-blog-header.php(13): require_once('/usr/www/users/...')
#8 /usr/www/users/smiczajxip/index.php(17): require('/usr/www/users/...')
#9 {main}
  thrown in /usr/www/users/smiczajxip/wp-content/plugins/health-check/includes/class-health-check-site-status.php on line 52