[gnome-builder] flatpak: ensure manifest prefix is prepopulated

[Christian Hergert <chergert src gnome org>]

commit 77920876d56419717fa6cc7256d3ae772d75a0f5
Author: Christian Hergert <chergert redhat com>
Date:   Tue Apr 10 18:57:04 2018 -0700

    flatpak: ensure manifest prefix is prepopulated
    
    Otherwise, when attaching the manifest (IdeConfiguration) to a runtime, it
    will get set and superficially emit a dirty/changed event.

 src/plugins/flatpak/gbp-flatpak-manifest.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/plugins/flatpak/gbp-flatpak-manifest.c b/src/plugins/flatpak/gbp-flatpak-manifest.c
index 7520bf069..3608e6ab6 100644
--- a/src/plugins/flatpak/gbp-flatpak-manifest.c
+++ b/src/plugins/flatpak/gbp-flatpak-manifest.c
@@ -645,6 +645,7 @@ gbp_flatpak_manifest_class_init (GbpFlatpakManifestClass *klass)
 static void
 gbp_flatpak_manifest_init (GbpFlatpakManifest *self)
 {
+  ide_configuration_set_prefix (IDE_CONFIGURATION (self), "/app");
 }
 
 GbpFlatpakManifest *