cli/trivial: align property definitions with spaces and not with tabs

Our coding style is to indent with tabs, but align with spaces.
This is not about the coding style though, but about the code
looking broken when not using 4 spaces per tab (in fact, some code
there is aligned as if using 8 spaces).

Realign with spaces.
15 jobs for th/nmcli-align-with-spaces
Status Job ID Name Coverage
  Test
canceled #476678
allowed to fail
checkpatch

manual #476683
allowed to fail manual
t_centos:7.5.1804
canceled #476684
t_centos:7.6.1810

canceled #476690
t_debian:10

canceled #476689
t_debian:9

canceled #476692
t_debian:sid

manual #476691
allowed to fail manual
t_debian:testing
canceled #476679
t_fedora:28

canceled #476680
t_fedora:29

canceled #476681
t_fedora:30

manual #476682
allowed to fail manual
t_fedora:rawhide
canceled #476685
t_ubuntu:16.04

canceled #476686
t_ubuntu:18.04

manual #476688
allowed to fail manual
t_ubuntu:devel
manual #476687
allowed to fail manual
t_ubuntu:rolling