public.js.flight: fix hovering over barogram for internet exploder <= 8
public.js.flight: fix hovering over barogram for internet exploder <= 8

The need of having a background-color set to enable mouse events is really silly...

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