[gimp] app: don't leak text-tool UI manager

[Ell <ell src gnome org>]

commit 8fa9221fb8f05a982d3481104ba5d94fd2cb1560
Author: Ell <ell_se yahoo com>
Date:   Tue May 19 17:05:17 2020 +0300

    app: don't leak text-tool UI manager

 app/tools/gimptexttool.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/app/tools/gimptexttool.c b/app/tools/gimptexttool.c
index eb557221e3..5398ab7d47 100644
--- a/app/tools/gimptexttool.c
+++ b/app/tools/gimptexttool.c
@@ -313,6 +313,7 @@ gimp_text_tool_finalize (GObject *object)
 
   g_clear_object (&text_tool->proxy);
   g_clear_object (&text_tool->buffer);
+  g_clear_object (&text_tool->ui_manager);
 
   gimp_text_tool_editor_finalize (text_tool);