[gimp/gimp-2-10] Installer: forgot about .xcf extension

[Jernej Simončič <jernejs src gnome org>]

commit c71a14622070627f832b49168a15ac6a6deb2248
Author: Jernej Simončič <jernej|s-gitstuff eternallybored org>
Date:   Sun Jun 16 09:18:38 2019 +0200

    Installer: forgot about .xcf extension

 build/windows/installer/associations.list | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/build/windows/installer/associations.list b/build/windows/installer/associations.list
index a40c0fdd90..bac7c26cec 100755
--- a/build/windows/installer/associations.list
+++ b/build/windows/installer/associations.list
@@ -1,3 +1,4 @@
+xcf
 bmp
 dds
 g3