[gupnp] Fix warning with clang

[Jens Georg <jensgeorg src gnome org>]

commit 82052b17607c20bc99ba32997eb4590c5f92b065
Author: Jens Georg <mail jensge org>
Date:   Sat May 10 18:30:24 2014 +0200

    Fix warning with clang

 libgupnp/gupnp-context-manager.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/libgupnp/gupnp-context-manager.c b/libgupnp/gupnp-context-manager.c
index e3cd54c..e766e93 100644
--- a/libgupnp/gupnp-context-manager.c
+++ b/libgupnp/gupnp-context-manager.c
@@ -582,9 +582,9 @@ gupnp_context_manager_create (guint port)
 #endif
         }
 #endif /* G_OS_WIN32 */
-        impl = g_object_new (impl_type,
-                             "port", port,
-                             NULL);
+        impl = GUPNP_CONTEXT_MANAGER (g_object_new (impl_type,
+                                                    "port", port,
+                                                    NULL));
 
 #if defined(USE_NETWORK_MANAGER) || defined(USE_CONNMAN)
         g_object_unref (system_bus);