[gimp-web] Advise using macOS DMG revision 1 for before BigSur.

[Jehan <jehanp src gnome org>]

commit d9a6d63accba10e453f6e038390a9add59dfad57
Author: Jehan <jehan girinstud io>
Date:   Fri Jan 22 12:58:11 2021 +0100

    Advise using macOS DMG revision 1 for before BigSur.

 content/gimp_versions.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/content/gimp_versions.json b/content/gimp_versions.json
index 9cc5046e..496e6f49 100644
--- a/content/gimp_versions.json
+++ b/content/gimp_versions.json
@@ -28,7 +28,7 @@
                     "sha256": "08ab7f6578b2852aaefd62e66a017f0a05794569d0f5449487371a00e5979586",
                     "min-support": "macOS 10.9 Mavericks",
                     "build-id": "org.gimp.GIMP_official",
-                    "comment" : "Some performance improvements on Big Sur",
+                    "comment" : "Some performance improvements on Big Sur, possible regressions reported on 
older macOS (use <a 
href='https://download.gimp.org/mirror/pub/gimp/v2.10/macos/gimp-2.10.22-x86_64-1.dmg'>Revision 1</a> instead 
if it's your case)",
                     "revision": 2
                 },
                 {