master 2888a2e076: Fix recent gamegrid.el change for nox build

[Basil L. Contovounesios]

branch: master
commit 2888a2e076e0ffea098b435b8b124acaeb6a5d0b
Author: Basil L. Contovounesios <contovob@tcd.ie>
Commit: Basil L. Contovounesios <contovob@tcd.ie>

    Fix recent gamegrid.el change for nox build
    
    * lisp/play/gamegrid.el (gamegrid-make-glyph): Declare
    image-scaling-factor as special before dynamically binding it, for
    the sake of --without-x builds which do not preload lisp/image.el.
---
 lisp/play/gamegrid.el | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lisp/play/gamegrid.el b/lisp/play/gamegrid.el
index 8da4205af5..8cff67c5bc 100644
--- a/lisp/play/gamegrid.el
+++ b/lisp/play/gamegrid.el
@@ -347,6 +347,8 @@ format."
           (gamegrid-match-spec-list (cdr spec-list)))))
 
 (defun gamegrid-make-glyph (data-spec-list color-spec-list)
+  ;; image.el is not preloaded in --without-x builds.
+  (defvar image-scaling-factor)
   (let ((data (gamegrid-match-spec-list data-spec-list))
        (color (gamegrid-match-spec-list color-spec-list))
         (image-scaling-factor 1.0))