Fix Button labels

src/chat_control.py

@@ -1874,7 +1874,7 @@ class ChatControl(ChatControlBase):
             file_props.name)
         if file_props.desc:
             markup += ' (%s)' % file_props.desc
-        b1 = Gtk.Button(_('_Open Containing Folder'))
+        b1 = Gtk.Button.new_with_mnemonic(_('_Open Containing Folder'))
         b1.connect('clicked', self._on_open_ft_folder, file_props)
         b2 = Gtk.Button(stock=Gtk.STOCK_OK)
         b2.connect('clicked', self._on_ok, file_props, 'file-completed')

src/filetransfers_window.py

@@ -214,7 +214,7 @@ class FileTransfersWindow:
         dialog = dialogs.HigDialog(None, Gtk.MessageType.INFO, Gtk.ButtonsType.NONE,
                         _('File transfer completed'), sectext)
         if file_props.type_ == 'r':
-            button = Gtk.Button(_('_Open Containing Folder'))
+            button = Gtk.Button.new_with_mnemonic(_('_Open Containing Folder'))
             button.connect('clicked', on_open, file_props)
             dialog.action_area.pack_start(button, True, True, 0)
         ok_button = dialog.add_button(Gtk.STOCK_OK, Gtk.ResponseType.OK)