[niepce] flatpak: bump glibmm to 2.58 to avoid FTBS

[Hubert Figuière <hub src gnome org>]

commit cc48fc0a96f7e3cf5126d3d9413d2561cee47e8f
Author: Hubert Figuière <hub figuiere net>
Date:   Sat Dec 22 17:22:51 2018 -0500

    flatpak: bump glibmm to 2.58 to avoid FTBS

 flatpak/org.gnome.Niepce.json | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/flatpak/org.gnome.Niepce.json b/flatpak/org.gnome.Niepce.json
index 13e4d4b..dc66686 100644
--- a/flatpak/org.gnome.Niepce.json
+++ b/flatpak/org.gnome.Niepce.json
@@ -142,8 +142,8 @@
             "sources" : [
                 {
                     "type" : "archive",
-                    "url" : "http://ftp.gnome.org/pub/GNOME/sources/glibmm/2.50/glibmm-2.50.1.tar.xz";,
-                    "sha256" : "1fd85051da9cb402cc8348cec72dfe4d79f9345df4a1dbf68703a4ded45846a4"
+                    "url" : "http://ftp.gnome.org/pub/GNOME/sources/glibmm/2.58/glibmm-2.58.0.tar.xz";,
+                    "sha256" : "d34189237b99e88228e6f557f7d6e62f767fe356f395a244f5ad0e486254b645"
                 }
             ]
         },