fix loginctl list-sessions parsing
Created by: baod-rate
right-aligned column from list-sessions command output can break parsing with tr and cut alone. e.g.:
$ loginctl list-sessions --no-legend
1 1000 foo seat0 tty1
464 1000 foo seat0 tty2
$ loginctl list-sessions --no-legend | tr -s " " | cut -d " " -f 1
464
$ loginctl list-sessions --no-legend | sed 's/^[[:space:]]*//; s/[[:space:]].*$//'
1
464