Fix LWUIT key release issue.

[com.sun.lwuit.Display.keyReleased](https://github.com/nokia-developer/lwuit-for-series-40/blob/master/Ports/Nokia/S40/src/com/sun/lwuit/Display.java#L1424) is never been called which causes
[com.sun.lwuit.Form.keyRepeated](https://github.com/nokia-developer/lwuit-for-series-40/blob/master/Ports/Nokia/S40/src/com/sun/lwuit/Display.java#L903) is invoked repeately.