uninstal xdebug

Uninstall php-xdebug

To remove just php-xdebug package itself from Ubuntu 16.04 (Xenial Xerus) execute on terminal:

sudo apt-get remove php-xdebug

Uninstall php-xdebug and it's dependent packages

To remove the php-xdebug package and any other dependant package which are no longer needed from Ubuntu Xenial.

sudo apt-get remove --auto-remove php-xdebug

Purging php-xdebug

If you also want to delete configuration and/or data files of php-xdebug from Ubuntu Xenial then this will work:

sudo apt-get purge php-xdebug

To delete configuration and/or data files of php-xdebug and it's dependencies from Ubuntu Xenial then execute:

sudo apt-get purge --auto-remove php-xdebug