[gimp] app: make gimp_gegl_get_config_proxy() work without a passed icon_name

[Michael Natterer <mitch src gnome org>]

commit d21ab943c1ba65aacb8eba2a13efd9dac95fd242
Author: Michael Natterer <mitch gimp org>
Date:   Sun Jan 17 16:09:03 2016 +0100

    app: make gimp_gegl_get_config_proxy() work without a passed icon_name
    
    Keeps the GEGL tool from crashing.

 app/gegl/gimp-gegl-config-proxy.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)
---
diff --git a/app/gegl/gimp-gegl-config-proxy.c b/app/gegl/gimp-gegl-config-proxy.c
index f2c3802..dec7751 100644
--- a/app/gegl/gimp-gegl-config-proxy.c
+++ b/app/gegl/gimp-gegl-config-proxy.c
@@ -199,7 +199,6 @@ gimp_gegl_get_config_proxy (const gchar *operation,
   GType config_type;
 
   g_return_val_if_fail (operation != NULL, NULL);
-  g_return_val_if_fail (icon_name != NULL, NULL);
   g_return_val_if_fail (g_type_is_a (parent_type, GIMP_TYPE_OBJECT), NULL);
 
   if (! config_types)
@@ -251,7 +250,7 @@ gimp_gegl_get_config_proxy (const gchar *operation,
         g_type_add_interface_static (config_type, GIMP_TYPE_CONFIG,
                                      &config_info);
 
-        if (g_type_is_a (config_type, GIMP_TYPE_VIEWABLE))
+        if (icon_name && g_type_is_a (config_type, GIMP_TYPE_VIEWABLE))
           {
             GimpViewableClass *viewable_class = g_type_class_ref (config_type);