#1 smx_message class : set_gpg_data() behavior wrong

[Joshua Gitlin]

in the smx_message class, member function set_gpg_data
*should* have the following behavior: unset the plain text
(because new encrypted text is coming in) and break sync. Then,
set the recipient list to the new recipients contained in the new
GPG data.

Actual behavior is to unset the message text and ignore the ACL
array, leaving the ACL status unknown.