fix(emacs): project relative path: return nil when not in project

modules/home/users/msyds/emacs/lisp/syd/prelude.el

@@ -202,7 +202,8 @@ form."
        s))))
 
 (defun syd-project-relative-file-name (file-name)
-  (file-relative-name file-name (project-root (project-current))))
+  (when-let* ((proj (project-current)))
+    (file-relative-name file-name (project-root proj))))
 
 (defvar syd-insert-file-name-alist
   `((,#'syd-project-relative-file-name . "Project-relative")