You can uninstall or removes an installed libldns-dev package itself from Debian 8 (Jessie) through the terminal,
$ sudo apt-get remove libldns-dev
If you would like to remove libldns-dev and it's dependent packages which are no longer needed from Ubuntu,
$ sudo apt-get remove --auto-remove libldns-dev
If you use with purge options to libldns-dev package all the configuration and dependent packages will be removed.
$ sudo apt-get purge libldns-dev
If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.
$ sudo apt-get purge --auto-remove libldns-dev