model/base: Moved columns iteration into weight_expression() function
model/base: Moved columns iteration into weight_expression() function

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