Fix compatibility with pre-1.11 iprop dump files

Fix compatibility with pre-1.11 iprop dump files

Ticket #7223 added new policy fields and a new dump format version to
marshal them, but did not add a new iprop dump format version.  As a
result, slave KDCs running 1.11 or later cannot receive full resyncs
from master KDCs running 1.10 or earlier.  (Reported by John
Devitofranceschi.)

Retroactively add support for pre-1.11 policy entries by making
process_r1_11_policy() read the first ten fields, check whether the
next whitespace character is a newline, and then read the rest if it
is not.

ticket: 8213
target_version: 1.13.3