[shotwell] flatpak: Update GPhoto2 to 2.5.20

[Jens Georg <jensgeorg src gnome org>]

commit 59ab112bfe9cacd706fa9a0f691bbd5ec9a3c43d
Author: Jens Georg <mail jensge org>
Date:   Fri Nov 23 10:50:40 2018 +0100

    flatpak: Update GPhoto2 to 2.5.20

 flatpak/org.gnome.Shotwell.json | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/flatpak/org.gnome.Shotwell.json b/flatpak/org.gnome.Shotwell.json
index be6d3830..887ce9f8 100644
--- a/flatpak/org.gnome.Shotwell.json
+++ b/flatpak/org.gnome.Shotwell.json
@@ -74,8 +74,8 @@
             "sources" : [
                 {
                     "type" : "archive",
-                    "url" : 
"https://datapacket.dl.sourceforge.net/project/gphoto/libgphoto/2.5.19/libgphoto2-2.5.19.tar.bz2";,
-                    "sha256" : "62523e52e3b8542301e072635b518387f2bd0948347775cf10cb2da9a6612c63"
+                    "url" : 
"https://datapacket.dl.sourceforge.net/project/gphoto/libgphoto/2.5.20/libgphoto2-2.5.20.tar.bz2";,
+                    "sha256" : "e10ff0140e2e5dddaf6c6d9d933ab6f8c0bc66fdf7445b1ef2ca9f4d96e68b0f"
                 }
             ],
             "config-opts" : [