packagegroup-connectivity: Bring back nmcli

Since ...

commit b68c4c76dbc294ca5ef1139e57689a9b005e22bd
Author: Christian Eggers <ceggers@arri.de>
Date:   Fri Jul 17 10:55:21 2020 +0200
    networkmanager: Package nmcli separately

... nmcli is packaged separately which made us drop it after the
kirkstone update. Bring it back by explicitely pulling it in the
packagegroup.

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>