QNX: Register for navigator events before any window creation

QNX: Register for navigator events before any window creation

This prevents a possible race condition in which the nvaigator service
notices that we have created a window and starts sending us messages
possibly before we have registered with bps for navigator messages.

This resulted in applications sometimes missing navigator messages at
startup.

Change-Id: I362fd782d7798990bc196f23e07b58293b13275d
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Reviewed-by: Nicolas Arnaud-Cormos <nicolas@kdab.com>