Correct typo in float JS glue (#1720)

Author: zoonderkins

NOTICE

@@ -34,6 +34,7 @@ under the licensing terms detailed in LICENSE:
 * Saúl Cabrera <saulecabrera@gmail.com>
 * Chance Snow <git@chancesnow.me>
 * Peter Salomonsen <petersalomonsen@runbox.com>
+* ookangzheng <git-ed@runbox.no>
 
 Portions of this software are derived from third-party works licensed under
 the following terms:

src/glue/js/float.js

@@ -1,5 +1,5 @@
 /**
- * @fileoverview Floating point glue code for JaavaScript.
+ * @fileoverview Floating point glue code for JavaScript.
  * @license Apache-2.0
  */