Checks if file exists in CopyOperation during "undo" execution

 * if file does not exist, do not try to remove it

Change-Id: I6f4afd11bd404994c2f732ded51f2fbd0d2373d6
Reviewed-by: Niels Weber <niels.weber@digia.com>
Reviewed-by: Tim Jenssen <tim.jenssen@digia.com>
Reviewed-by: Karsten Heimrich <karsten.heimrich@digia.com>