[pitivi] flatpak: Build meson 0.46.0 as it is required for GStreamer master.

[Thibault Saunier <tsaunier src gnome org>]

commit 3e2dd3fe163efe89feef04ce062d2de6b6b38fd8
Author: Thibault Saunier <tsaunier igalia com>
Date:   Thu May 3 11:03:11 2018 +0200

    flatpak: Build meson 0.46.0 as it is required for GStreamer master.
    
    And call the flathub repo... flathub!

 build/flatpak/org.pitivi.Pitivi.json | 18 ++++++++++++++++++
 build/flatpak/pitivi-flatpak         |  2 +-
 2 files changed, 19 insertions(+), 1 deletion(-)
---
diff --git a/build/flatpak/org.pitivi.Pitivi.json b/build/flatpak/org.pitivi.Pitivi.json
index e53226ea..de6dfa9f 100644
--- a/build/flatpak/org.pitivi.Pitivi.json
+++ b/build/flatpak/org.pitivi.Pitivi.json
@@ -190,6 +190,24 @@
                 }
             ]
         },
+        {
+            "name": "meson",
+            "build-options": {
+                "build-args": [
+                    "--share=network"
+                ]
+            },
+            "config-opts": [
+                "--module=meson==0.46.0"
+            ],
+            "sources": [
+                {
+                    "type": "file",
+                    "path": "py-configure",
+                    "dest-filename": "configure"
+                }
+            ]
+        },
         {
             "name": "sound-theme-freedesktop",
             "ensure-writable": [
diff --git a/build/flatpak/pitivi-flatpak b/build/flatpak/pitivi-flatpak
index 091dac15..c302c8d9 100755
--- a/build/flatpak/pitivi-flatpak
+++ b/build/flatpak/pitivi-flatpak
@@ -409,7 +409,7 @@ class PitiviFlatpak:  # pylint: disable=too-many-instance-attributes
         self.check_flatpak()
 
         repos = FlatpakRepos()
-        self.sdk_repo = repos.add("gnome",
+        self.sdk_repo = repos.add("flathub",
                                   "https://dl.flathub.org/repo/flathub.flatpakrepo";)
 
         sdk_branch = SDK_BRANCH[self.branch]