Fix KDC worker process argument parsing

To create worker processes, the KDC shuts down realms, forks off the
worker processes, then reinitializes realms in each child.
Reinitializing realms requires making a second pass over the
command-line arguments.  To do this with getopt, optind must be
reinitialized to 1 for each pass; otherwise, no options will be seen
the second time around.

(cherry picked from commit 1776fd19120d230115527febbd22979eb64ee1ff)

https://github.com/krb5/krb5/commit/d749fa1a6442a920592d34a8f43aa857a56be044
Author: Greg Hudson <ghudson@mit.edu>
Committer: Tom Yu <tlyu@mit.edu>
Commit: d749fa1a6442a920592d34a8f43aa857a56be044
Branch: krb5-1.12
 src/kdc/main.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)