[gimp] desktop: update appdata with dates.

[Jehan <jehanp src gnome org>]

commit 588626dec10632166cd929359d671a9dba4b2d43
Author: Jehan <jehan girinstud io>
Date:   Tue Dec 22 20:55:06 2020 +0100

    desktop: update appdata with dates.

 desktop/org.gimp.GIMP.appdata.xml.in.in | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/desktop/org.gimp.GIMP.appdata.xml.in.in b/desktop/org.gimp.GIMP.appdata.xml.in.in
index 3c5e0eb8f3..224ff8a73f 100644
--- a/desktop/org.gimp.GIMP.appdata.xml.in.in
+++ b/desktop/org.gimp.GIMP.appdata.xml.in.in
@@ -73,8 +73,8 @@
   </provides>
 
   <releases>
-    <release version="2.99.4" date="TODO" type="development">
-      <url type="details">https://www.gimp.org/news/2020/TODO/gimp-2-99-4-released/</url>
+    <release version="2.99.4" date="2020-12-22" type="development">
+      <url type="details">https://www.gimp.org/news/2020/12/25/gimp-2-99-4-released/</url>
       <description>
         <_p>
         This second development release contains various usability and API updates.