[evince] flatpak: Fix reproducibility on webp-pixbuf-loader

[Germán Poo-Caamaño <gpoo src gnome org>]

commit 7d2e2b5a606704a2aeece5518d0ae3bd2cbcf28f
Author: Germán Poo-Caamaño <gpoo gnome org>
Date:   Thu Oct 11 11:58:11 2018 -0300

    flatpak: Fix reproducibility on webp-pixbuf-loader

 build-aux/flatpak/org.gnome.Evince.json | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/build-aux/flatpak/org.gnome.Evince.json b/build-aux/flatpak/org.gnome.Evince.json
index 57c898f7..4e886e26 100644
--- a/build-aux/flatpak/org.gnome.Evince.json
+++ b/build-aux/flatpak/org.gnome.Evince.json
@@ -88,7 +88,8 @@
             "sources": [
                 {
                     "type": "git",
-                    "url": "https://github.com/aruiz/webp-pixbuf-loader.git";
+                    "url": "https://github.com/aruiz/webp-pixbuf-loader.git";,
+                    "commit": "9b92950d49d7939f90ba7413deb7ec6b392b2054"
                 }
             ],
             "post-install": [
@@ -197,4 +198,4 @@
             ]
         }
     ]
-}
\ No newline at end of file
+}