redhat: Use a secure URL to retrieve CellServDB

redhat: Use a secure URL to retrieve CellServDB

By default, makesrpm.pl will use wget to retrieve the CellServDB
as specified in the spec file. Even though the script need not and
thus should not be run by a privileged UID, make this a bit more
secure by specifying an https URL.

Reviewed-on: https://gerrit.openafs.org/12329
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: Benjamin Kaduk <kaduk@mit.edu>
(cherry picked from commit 16463b602a210768f80bec9ef7c6896ea8a9909d)

Change-Id: I13d924d6a8e3b5ac31359a85b9a07ee041570b61
Reviewed-on: https://gerrit.openafs.org/12330
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>