Update filesystem.go
Update filesystem.go

bugfix: .Files() called twice in line 253, 256 in site.go. thus source files captured twice.

Signed-off-by: Noah Campbell <139a6acca76faf214b165dcdff156ecf06d23690@gmail.com>

gohugoio/hugo,anthonyfok/hugo,tatsushid/hugo,abourget/hugo,anthonyfok/hugo,ryanclarke/hugo,ffrizzo/hugo,mayah/hugo,fhergomez/hugo,ffrizzo/hugo,fedelibre/hugo,tjyang/hugo,halostatue/hugo,gohugoio/hugo,kujohn/hugo,tischda/hugo,Zenithar/hugo,soundrussian/hugo,jygastaud/hugo,tubo028/hugo,bogem/hugo,coderzh/hugo,mdhender/hugo,fedelibre/hugo,ifraixedes/hugo,Zenithar/hugo,anthonyfok/hugo,ryanclarke/hugo,fhergomez/hugo,bramp/hugo,halostatue/hugo,derekperkins/hugo,mdhender/hugo,sprig/hugo,mitchchn/hugo,vbatoufflet/hugo,bogem/hugo,mayah/hugo,MarkDBlackwell/hugo,tatsushid/hugo,fedelibre/hugo,mdhender/hugo,mitchchn/hugo,tubo028/hugo,gohugoio/hugo,kujohn/hugo,vbatoufflet/hugo,coderzh/hugo,badoet/hugo,melo/hugo,tjyang/hugo,mdhender/hugo,soundrussian/hugo,melo/hugo,digitalcraftsman/hugo,MarkDBlackwell/hugo,derekperkins/hugo,bramp/hugo,abourget/hugo,fedelibre/hugo,digitalcraftsman/hugo,jygastaud/hugo,sprig/hugo,tischda/hugo,badoet/hugo,ifraixedes/hugo