Your PHP installation appears to be missing the MySQL extension which is required by WordPress.
This is what I get when I try to install WP.
The server is running.
Centos 6.7 x64.
Litespeed Standard Edition.
MariaDB.
I learned that php-mysql is required. So I installed php-mysql.
# rpm -qa | grep php-mysql
php-mysql-5.3.3-46.el6_6.x86_64
# tail mysqli.ini
; Enable mysqli extension module
extension=mysqli.so
Also in phpinfo()
I have this.
Loaded Configuration File (none)
Scan this dir for additional .ini files (none)
Additional .ini files parsed (none)
Do I need to rebuild PHP? Am I missing anything else?