Fix Hints mode mappings.

common/content/hints.js

@@ -1239,6 +1239,10 @@ var Hints = Module("hints", {
             function ({ count }) { hints.open("g;", { continue: true, count: count }); },
             { count: true });
 
+        let bind = function bind(names, description, action, params)
+            mappings.add([modes.HINTS], names, description,
+                         action, params);
+
         bind(["<Return>"],
             "Follow the selected hint",
             function ({ self }) { self.update(true); });