No. Changing the transactions in a block does not improve or reduce luck. This is superstition.

Someone also suggested that deleting wallet.dat and starting over once in a while improves luck with mining. This is also superstition.

It's normal to have some unlucky rounds just like it is normal to have some lucky rounds.

Note: the above is a simplification and not strictly true. IF you can find a weakness in the SHA-256 algorithm you may be able to improve success with mining. You can read about it at http://en.wikipedia.org/wiki/Sha-256 and try to find a way to break it. I bet that since Bitcoin became valuable more people than ever are trying to do this.