QmlCppEngine: Properly handle requestRemoteSetupCalls

Remember which engines called requestRemoteSetup.

Change-Id: I75d11a21f0ebcbce1bba0aa4f653d1cc35b43483
Reviewed-by: Aurindam Jana <aurindam.jana@nokia.com>
Reviewed-by: hjk <qthjk@ovi.com>
Reviewed-by: Christiaan Janssen <christiaan.janssen@nokia.com>