[gnome-todo] workspace: Fix mismatching required types

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 56b4687a16992ba73662505ef0ddea04aad35af1
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Sun May 3 14:52:57 2020 -0300

    workspace: Fix mismatching required types

 src/interfaces/gtd-workspace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/interfaces/gtd-workspace.c b/src/interfaces/gtd-workspace.c
index bb02171..8624245 100644
--- a/src/interfaces/gtd-workspace.c
+++ b/src/interfaces/gtd-workspace.c
@@ -20,7 +20,7 @@
 
 #include "gtd-workspace.h"
 
-G_DEFINE_INTERFACE (GtdWorkspace, gtd_workspace, G_TYPE_OBJECT)
+G_DEFINE_INTERFACE (GtdWorkspace, gtd_workspace, GTK_TYPE_WIDGET)
 
 static void
 gtd_workspace_default_init (GtdWorkspaceInterface *iface)