lib/igc: Don't calculate gilder_type_clean if not used any further
lib/igc: Don't calculate gilder_type_clean if not used any further

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