keyboard: Fix JS warning

The label field may be empty here (eg. buttons fully styled through css),
just resort to an empty string then.

diff --git a/js/ui/keyboard.js b/js/ui/keyboard.js
index cbfdb091443bdcc743e18f902b7d767371d3ffc7..a37580b32aa591d9b77ae5cc7dcf3b89d8d9fecf 100644 (file)
--- a/js/ui/keyboard.js
+++ b/js/ui/keyboard.js
@@ -802,7 +802,7 @@ var Keyboard = class Keyboard {
             let switchToLevel = key.level;
             let action = key.action;
 
-            extraButton = new Key(key.label, []);
+            extraButton = new Key(key.label || '', []);
 
             extraButton.keyButton.add_style_class_name('default-key');
             if (key.extraClassName != null)