[gnome-boxes] Fix warnings about non-handled exception

[Alexander Larsson <alexl src gnome org>]

commit 14cd13c8c9ae6131a3aa50a697be602c1e8e6535
Author: Alexander Larsson <alexl redhat com>
Date:   Mon Nov 19 11:08:10 2012 +0100

    Fix warnings about non-handled exception
    
    https://bugzilla.gnome.org/show_bug.cgi?id=672268

 src/spice-display.vala |   19 +++++++++++--------
 1 files changed, 11 insertions(+), 8 deletions(-)
---
diff --git a/src/spice-display.vala b/src/spice-display.vala
index 528d5d3..a262e47 100644
--- a/src/spice-display.vala
+++ b/src/spice-display.vala
@@ -41,14 +41,17 @@ private class Boxes.SpiceDisplay: Boxes.Display {
         session = new Session ();
         audio = Spice.Audio.get (session, null);
         gtk_session = GtkSession.get (session);
-        var manager = UsbDeviceManager.get (session);
-        manager.auto_connect_failed.connect ( (dev, err) => {
-            got_error (err.message);
-        });
+        try {
+            var manager = UsbDeviceManager.get (session);
+            manager.auto_connect_failed.connect ( (dev, err) => {
+                    got_error (err.message);
+            });
 
-        manager.device_error.connect ( (dev, err) => {
-            got_error (err.message);
-        });
+            manager.device_error.connect ( (dev, err) => {
+                    got_error (err.message);
+            });
+        } catch (GLib.Error error) {
+        }
 
         this.notify["config"].connect (() => {
             config.sync_properties (gtk_session, gtk_session_sync_properties);