QtIFW

Don't copy over a checksum file.

Whithout this fix, offline installers would spam the install
directory with .sha1 files. Follow up on 61dc9d1d03f039e5155

Change-Id: Ice1bc51e1d058b48b2a58849611b7005d290f8c1
Reviewed-by: Niels Weber <niels.2.weber@nokia.com>
Reviewed-by: Tim Jenssen <tim.jenssen@nokia.com>