project_openldap: fix try/catch block

[simonLeary42]

I noticed these pyright errors:

project_openldap_sync.py:153:34 - error: "archive_posixgroup_dn" is possibly unbound (reportPossiblyUnboundVariable)
project_openldap_sync.py:157:34 - error: "archive_posixgroup_dn" is possibly unbound (reportPossiblyUnboundVariable)
project_openldap_sync.py:164:48 - error: "archive_posixgroup_dn" is possibly unbound (reportPossiblyUnboundVariable)
project_openldap_sync.py:168:85 - error: "archive_ou_dn" is possibly unbound (reportPossiblyUnboundVariable)
project_openldap_sync.py:169:57 - error: "archive_ou_dn" is possibly unbound (reportPossiblyUnboundVariable)
project_openldap_sync.py:169:72 - error: "archive_openldap_ou_description" is possibly unbound (reportPossiblyUnboundVariable)
project_openldap_sync.py:172:93 - error: "archive_posixgroup_dn" is possibly unbound (reportPossiblyUnboundVariable)
project_openldap_sync.py:174:21 - error: "archive_posixgroup_dn" is possibly unbound (reportPossiblyUnboundVariable)
project_openldap_sync.py:175:21 - error: "archive_openldap_posixgroup_description" is possibly unbound (reportPossiblyUnboundVariable)
project_openldap_sync.py:176:21 - error: "archive_gid" is possibly unbound (reportPossiblyUnboundVariable)
project_openldap_sync.py:180:55 - error: "archive_posixgroup_dn" is possibly unbound (reportPossiblyUnboundVariable)

It seems that in the event of an exception, the sync command will print the exception and then keep running and then crash when it refers to these variables.

[simonLeary42]

from @ds-04 (author of project_openldap) in Slack:

yeah think this looks fine.. since it evaluates on a per project basis ..