Fix uninitialized flags in MSLSA ccache type

Fix uninitialized flags in MSLSA ccache type

The flags field in krb5_lcc_data is not initialized in
krb5_lcc_resolve(), so krb5_lcc_next_cred() can sometimes fail to
include a ticket when retrieving a ccache entry.  This results in a
"Request did not supply a ticket" error from k5_make_tgs_req() when
trying to use the credential.

[ghudson@mit.edu: condensed commit message]

ticket: 8567
target_version: 1.13-next
target_version: 1.14-next
target_version: 1.15-next
tags: pullup