[recipes] Avoid a compiler warning

[Matthias Clasen <matthiasc src gnome org>]

commit 9d89cd66efa67c9f6e3d304ad8268da35bc12285
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Mar 15 12:48:42 2017 -0400

    Avoid a compiler warning
    
    message1 looked like it might be used uninitialized.

 src/gr-utils.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/src/gr-utils.c b/src/gr-utils.c
index 22f0c72..5b75378 100644
--- a/src/gr-utils.c
+++ b/src/gr-utils.c
@@ -461,6 +461,8 @@ portal_available (GtkWindow  *window,
                 message1 = _("Missing the desktop portal needed to print from inside a Flatpak sandbox.");
         else if (strcmp (interface, "org.freedesktop.portal.OpenURI") == 0)
                 message1 = _("Missing the desktop portal needed to open URLs from inside a Flatpak 
sandbox.");
+        else
+                message1 = "";
 
         message2 = _("Please install xdg-desktop-portal and xdg-desktop-portal-gtk on your system");