[gimp] app: fix new g_object_ref() warnings in gimp_filter_tool_edit_as()

[Michael Natterer <mitch src gnome org>]

commit 9090a98498e5399a06c395880505d3b157cfda1f
Author: Michael Natterer <mitch gimp org>
Date:   Sun Apr 1 14:55:11 2018 +0200

    app: fix new g_object_ref() warnings in gimp_filter_tool_edit_as()
    
    g_object_ref() now returns the same type that was passed in. Cast the
    argument to GObject* to match the variable the return value is
    assigned to.

 app/tools/gimpfiltertool.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/app/tools/gimpfiltertool.c b/app/tools/gimpfiltertool.c
index a090c3a..88440e5 100644
--- a/app/tools/gimpfiltertool.c
+++ b/app/tools/gimpfiltertool.c
@@ -1489,7 +1489,7 @@ gimp_filter_tool_edit_as (GimpFilterTool *filter_tool,
 
   new_tool = tool_manager_get_active (display->gimp);
 
-  GIMP_FILTER_TOOL (new_tool)->default_config = g_object_ref (config);
+  GIMP_FILTER_TOOL (new_tool)->default_config = g_object_ref (G_OBJECT (config));
 
   gimp_filter_tool_reset (GIMP_FILTER_TOOL (new_tool));
 }