[gimp] app: remove the split preview guide in gimp_filter_tool_get_operation()

[Michael Natterer <mitch src gnome org>]

commit 82fde3e6c4fa2987ac55477ab244cf0a87039588
Author: Michael Natterer <mitch gimp org>
Date:   Fri Jan 5 14:10:12 2018 +0100

    app: remove the split preview guide in gimp_filter_tool_get_operation()
    
    so when switching ops in the GEGL tool, the new one doesn't show a
    guide that does nothing until one toggles "Split view" twice.

 app/tools/gimpfiltertool.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/app/tools/gimpfiltertool.c b/app/tools/gimpfiltertool.c
index ecbd067..15d668f 100644
--- a/app/tools/gimpfiltertool.c
+++ b/app/tools/gimpfiltertool.c
@@ -736,7 +736,6 @@ gimp_filter_tool_options_notify (GimpTool         *tool,
               g_object_set (options,
                             "preview-position", CLAMP (position, 0.0, 1.0),
                             NULL);
-
             }
         }
 
@@ -1347,6 +1346,8 @@ gimp_filter_tool_get_operation (GimpFilterTool *filter_tool)
     {
       gimp_drawable_filter_abort (filter_tool->filter);
       g_clear_object (&filter_tool->filter);
+
+      gimp_filter_tool_remove_guide (filter_tool);
     }
 
   g_clear_object (&filter_tool->operation);