[gimp] fix typo

[Simon Budig <simon src gnome org>]

commit 75853eec0143974b9bbc93a28d4c9857837f6d91
Author: Simon Budig <simon budig de>
Date:   Tue Sep 27 02:27:09 2016 +0200

    fix typo

 app/tools/gimpwarptool.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/app/tools/gimpwarptool.c b/app/tools/gimpwarptool.c
index 842b3ba..e0a7aa6 100644
--- a/app/tools/gimpwarptool.c
+++ b/app/tools/gimpwarptool.c
@@ -725,7 +725,7 @@ gimp_warp_tool_create_graph (GimpWarpTool *wt)
 
   render = gegl_node_new_child (graph,
                                 "operation", "gegl:map-relative",
-                                "sampler_type", GEGL_SAMPLER_LINEAR,
+                                "sampler-type", GEGL_SAMPLER_LINEAR,
                                 NULL);
 
   gegl_node_connect_to (input,  "output",