Fix section_occupancy: Return empty table

Fixes the functioning of the LuaATC function section_occupancy in
the presence of no trains.

Currently, if there is no train in the section,
advtrains.interlocking.db.get_ts will return a table with a nil entry.
When that nil value is passed to table.copy, Minetest throws out an error.
Instead of passing nil to table.copy, just make a new empty table.

0 files changed, 0 insertions, 0 deletions