[Options] Remove unused CSS.
[Options] Remove unused CSS.

VPashkov/vimium,jb55/vimium-plus,csmalin/vimium,willsALMANJ/vimium,douglas-larocca/vimium,Lw-Cui/vimium,bkudria/vimium,wildeyes/vimium,poacher2k/vimium,justalittlenoob/vimium,justalittlenoob/vimium,tuchangwei/vimium,zhangmin510/vimium,borgified/vimium,PrestanceDesign/vimium,philc/vimium,hhsue/vimium,cyrixhero/vimium,smblott-github/vimium-smblott,borgified/vimium,Lw-Cui/vimium,VPashkov/vimium,willsALMANJ/vimium,Robinson10240/vimium,wildeyes/vimium,elderbas/vimium,smblott-github/vimium,smblott-github/vimium,bkudria/vimium,poacher2k/vimium,douglas-larocca/vimium,Lw-Cui/vimium,PrestanceDesign/vimium,jb55/vimium-plus,mrmr1993/vimium,philc/vimium,hhsue/vimium,Aleroniponi/vimium,dimatter/vimium,decaffeinate-examples/vimium,smblott-github/vimium,Aleroniponi/vimium,decaffeinate-examples/vimium,PickRelated/vimium,crazypenguincode/vimium,PrestanceDesign/vimium,borgified/vimium,willsALMANJ/vimium,hhsue/vimium,elegantwww/vimium,douglas-larocca/vimium,tuchangwei/vimium,smblott-github/vimium-smblott,csmalin/vimium,Aleroniponi/vimium,justalittlenoob/vimium,philc/vimium,VPashkov/vimium,wildeyes/vimium,zhangmin510/vimium,dimatter/vimium,PickRelated/vimium,decaffeinate-examples/vimium,zhangmin510/vimium,gdh1995/vimium,crazypenguincode/vimium,elegantwww/vimium,csmalin/vimium,PickRelated/vimium,mrmr1993/vimium,mrmr1993/vimium,poacher2k/vimium,bkudria/vimium,cyrixhero/vimium,tuchangwei/vimium,elegantwww/vimium,cyrixhero/vimium,Robinson10240/vimium,elderbas/vimium,gdh1995/vimium,Robinson10240/vimium,elderbas/vimium,dimatter/vimium,gdh1995/vimium