Forcing testnet for pre-release versions of the wallet.
In clientversion.h we have a flag for pre-release versions.
CLIENT_VERSION_IS_RELEASE = false
What we need to do here is if this flag is set to true, we need to also force testnet = 1 in the wallet.
Pretty sure we just need to modify this block of code so that if CLIENT_VERSION_IS_RELEASE = false then we also force testnet.