Summary:
* Add missing include for used class
* Remove unnecessary dependency on libkf5networkmanagerqt-dev
Test Plan:
1. Check that the build does not fail.
2. Check that it has the same behaviour as before.
Reviewers: wxl, tsimonq2, hmollercl
Reviewed By: tsimonq2
Differential Revision: https://phab.lubuntu.me/D53
apt-ghetto