flight.js: fix getNextSmallerIndex again.
flight.js: fix getNextSmallerIndex again.

This method doesn't do what it's said to do: it returns the next
smaller index to value in array but at least 0.

skylines-project/skylines,Turbo87/skylines,skylines-project/skylines,RBE-Avionik/skylines,kerel-fs/skylines,Turbo87/skylines,Turbo87/skylines,kerel-fs/skylines,kerel-fs/skylines,snip/skylines,RBE-Avionik/skylines,Harry-R/skylines,shadowoneau/skylines,snip/skylines,TobiasLohner/SkyLines,shadowoneau/skylines,Harry-R/skylines,Harry-R/skylines,TobiasLohner/SkyLines,Harry-R/skylines,snip/skylines,shadowoneau/skylines,TobiasLohner/SkyLines,shadowoneau/skylines,skylines-project/skylines,RBE-Avionik/skylines,Turbo87/skylines,RBE-Avionik/skylines,skylines-project/skylines