v1.21.3

Changes:
Simplify vscript stub function (Launcher#627)

Fixes:
Fix spectating for LTS (Mods#774)
Add validity check to SaveStatsPeriodically_Threaded (Mods#769)
Add validity check to HandleDistanceAndTimeStats_Threaded to prevent crash (Mods#767)

Translation updates:
Translations update from Weblate (Mods#776)

Contributors:
@ASpoonPlaysGames @CTalvio @Khalmee @L1ghtman2k @harmony-weblate