Fixed bug that wasn't showing the StaticRootPath when validation failed

pkg/setting/setting.go

@@ -386,7 +386,7 @@ func validateStaticRootPath() error {
 		return nil
 	}
 
-	return errors.New("Failed to detect generated css or javascript files in static root (%s), have you executed default grunt task?")
+	return fmt.Errorf("Failed to detect generated css or javascript files in static root (%s), have you executed default grunt task?", StaticRootPath)
 }
 
 func NewConfigContext(args *CommandLineArgs) error {