Use fsx package and friends from pkglib

internal/config/validators/files.go

@@ -1,15 +1,15 @@
 package validators
 
 import (
-	"github.com/FAU-CDI/wisski-distillery/pkg/fsx"
 	"github.com/pkg/errors"
+	"github.com/tkw1536/pkglib/fsx"
 )
 
 func ValidateFile(path *string, dflt string) error {
 	if *path == "" {
 		*path = dflt
 	}
-	if !fsx.IsFile(*path) {
+	if !fsx.IsRegular(*path) {
 		return errors.Errorf("%q does not exist or is not a file", *path)
 	}
 	return nil