hugolib: Remove extraneous createStaticFs call

This looks like a copy+paste error.  We have the same line a few lines
below this call and we actually handle the err value there.

hugolib/filesystems/basefs.go

@@ -383,8 +383,6 @@ func (b *sourceFilesystemsBuilder) Build() (*SourceFilesystems, error) {
 
 	b.result.Resources = sfs
 
-	err = b.createStaticFs()
-
 	sfs, err = b.createFs(false, true, "", "")
 	if err != nil {
 		return nil, err