[pitivi] build: Answer automatically y/n questions when updating SDKs

[Alexandru Băluț <alexbalut src gnome org>]

commit 1decf7e2a9d9f139608a1d634e10e73cc7ff9423
Author: Alexandru Băluț <alexandru balut gmail com>
Date:   Sat Jul 21 02:14:44 2018 +0200

    build: Answer automatically y/n questions when updating SDKs
    
    For example:
    flatpak update --user org.gnome.Platform 3.28
    Updating in user:
    org.gnome.Platform/x86_64/3.28                       flathub 4afe5ccb6990
    org.gnome.Platform.Locale/x86_64/3.28                flathub 1d96abcdc97b
    Is this ok [y/n]:

 build/flatpak/pitivi-flatpak | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/build/flatpak/pitivi-flatpak b/build/flatpak/pitivi-flatpak
index 6da07fcc..69f65341 100755
--- a/build/flatpak/pitivi-flatpak
+++ b/build/flatpak/pitivi-flatpak
@@ -348,7 +348,7 @@ class FlatpakPackage(FlatpakObject):
             self.install()
             return
 
-        self.flatpak("update", self.name, self.branch, show_output=True,
+        self.flatpak("update", self.name, self.branch, "-y", show_output=True,
                      comment="Updating %s" % self.name)
 
     def run_app(self, *args):