x11/lightdm: Fix packaging with non default options

When VAPI is on and DOCS is off the port fails to package. Correct
in plist. [1]

While here also implement an NLS option.

PR: 277022 [1]
MFH: 2024Q1
(cherry picked from commit 9b0bf17a5c4eebafdfe5b4e5463002e169857295)