tables.css: fix table sorting header style
tables.css: fix table sorting header style

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