ceph-deploy.spec: use spaces instead of tabs

ceph-deploy.spec: use spaces instead of tabs

This fixes the following rpmlint warning:

  ceph-deploy.spec:15: W: mixed-use-of-spaces-and-tabs (spaces: line 15,
  tab: line 13)

More information from rpmlint's "-I" (help) command:

  $ rpmlint -I mixed-use-of-spaces-and-tabs
  mixed-use-of-spaces-and-tabs:
  The specfile mixes use of spaces and tabs for indentation, which is a
  cosmetic annoyance.  Use either spaces or tabs for indentation, not
  both.

Signed-off-by: Ken Dreyer <kdreyer@redhat.com>