update label "Minimum space between numbering and text"

Change-Id: I7e51c47848a3454dace8f6f86a5d434a8ff37b6d
Reviewed-on: https://gerrit.libreoffice.org/12141
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>