kcms/nightcolor: Fix nighcolor typos and warnings
- Fix the latitude->longitud typo
- Properly type the Geolocator as a QtObject property
- Check for the locator object trueness, not just undefinedness
- Remove the conditions based on
doneLoading
to avoid a race condition
Amends: cb2b0e9c
Submitting this "inverse" cherry-pick as an alternative to the bugfix part in !3487, as the bug is affecting the review of !3504 (merged).
(cherry picked from commit 273855ce)