Commit 829e95b dropped a test for game_mode_hoard when computing light.
Since hoard orbs are in a union which overlaps the score in mission
mode, this caused a bug where a player in mission mode with non-zero
score would pulse light like a player carrying orbs in hoard mode.
Restore the test for hoard mode.
Fixes: 829e95b6f8 ("Separate hoard/proximity tracking")