Ticket #2405: fixed key event handling in "Listing mode" dialog.

Typing 'u' in "User defined mode" input line, the "User defined"
radio-button is checked instead of putting the 'u' letter
into the input line.

Bug was introduced in 80d34ca6256e6a95a15b480cf5f3cae642fe5b2d.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>

src/boxes.c

@@ -106,7 +106,8 @@ display_callback (Dlg_head * h, Widget * sender, dlg_msg_t msg, int parm, void *
             }
         }
 
-        if (g_ascii_tolower (parm) == display_user_hotkey)
+        if ((g_ascii_tolower (parm) == display_user_hotkey)
+            && dlg_widget_active (display_user_format) && dlg_widget_active (display_mini_status))
         {
             display_radio->pos = display_radio->sel = 3;
             dlg_select_widget (display_radio);  /* force redraw */