Revert "AddScripts should not attempt to override already set redeem scripts"
Revert "AddScripts should not attempt to override already set redeem scripts"

This reverts commit 53ba6109f521027052f0d5d762c4faee0b4299d3.

MetacoSA/NBitcoin,MetacoSA/NBitcoin,NicolasDorier/NBitcoin