Revert "Actually use mapAlreadyAskedFor."
Revert "Actually use mapAlreadyAskedFor."

This reverts commit 643160f6e7e5e8ca84bc7d2c1a0f37d9cf43a6e1.

Turns out this commit was useless after a more careful reading of
CNode::AskFor

MidasPaymentLTD/midascoin,MidasPaymentLTD/midascoin,MidasPaymentLTD/midascoin,MidasPaymentLTD/midascoin,MidasPaymentLTD/midascoin