[gimp] build: update base dependencies to fix flatpak.

[Jehan Pagès <jehanp src gnome org>]

commit 9dfd35be054125ab7ba8b5201490ffae96a74056
Author: Jehan <jehan girinstud io>
Date:   Mon Apr 9 04:02:36 2018 +0200

    build: update base dependencies to fix flatpak.

 build/flatpak/flathub |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/build/flatpak/flathub b/build/flatpak/flathub
index f3016af..19dcc22 160000
--- a/build/flatpak/flathub
+++ b/build/flatpak/flathub
@@ -1 +1 @@
-Subproject commit f3016af77c684beafd8e26dfc990317305687350
+Subproject commit 19dcc22b60e69eaaf740d4311021ed55b7e2537d