[gnome-latex] LaTeX commands: Avoid superfluous and fatal cast to Gtk.Activatable

[Sébastien Wilmet <swilmet src gnome org>]

commit 02f35b9dc60eab0cf741e44740e12c91daf9ea8e
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Tue May 8 17:15:42 2018 +0200

    LaTeX commands: Avoid superfluous and fatal cast to Gtk.Activatable
    
    Fixes https://gitlab.gnome.org/GNOME/gnome-latex/issues/58
    
    See also:
    https://bugzilla.gnome.org/show_bug.cgi?id=795920

 src/latex_menu.vala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/latex_menu.vala b/src/latex_menu.vala
index f965d23..4480dc8 100644
--- a/src/latex_menu.vala
+++ b/src/latex_menu.vala
@@ -500,7 +500,7 @@ public class LatexMenu : Gtk.ActionGroup
     private Gtk.Action get_menu_tool_action (string name, string? label, string? icon_name)
     {
         Gtk.Action action = new MenuToolAction (name, label, label, icon_name);
-        Activatable menu_tool_button = (Activatable) new MenuToolButton (null, null);
+        MenuToolButton menu_tool_button = new MenuToolButton (null, null);
         menu_tool_button.set_related_action (action);
         return action;
     }