Set TL_DATA mask flag for master key operations

Set TL_DATA mask flag for master key operations

When kdb5_util adds or removes master keys, it modifies tl-data but
doesn't set the KADM5_TL_DATA mask flag, causing KDB modules that rely
on this signaling (such as the LDAP module) not to store the tl-data
changes.  Fix this issue by setting the mask bit in add_new_mkey() and
kdb5_purge_mkeys().

[ghudson@mit.edu: edit commit message]

(cherry picked from commit c877f13c8985d820583b0d7ac1bb4c5dc36e677e)

ticket: 8327
version_fixed: 1.14.1