svc-map: do not specify user/group for install
svc-map: do not specify user/group for install

Since install is run as root already (using sudo), the resulting file
will be already root:root.

Change-Id: I6023fd277ea77fbfa4f7ad42b04d58c8cd6bd4fe

switch-ch/diskimage-builder,takahashinobuyuki/diskimage-builder,switch-ch/diskimage-builder,takahashinobuyuki/diskimage-builder,zioproto/diskimage-builder,openstack/diskimage-builder,CSC-IT-Center-for-Science/diskimage-builder,CSC-IT-Center-for-Science/diskimage-builder,openstack/diskimage-builder,zioproto/diskimage-builder