Pruning changes trie without digests (#952)

* pruning changes tries without digests

* u64::max_value()

substrate/srml/balances/src/mock.rs

@@ -104,7 +104,6 @@ impl ExtBuilder {
 			transfer_fee: self.transfer_fee,
 			creation_fee: self.creation_fee,
 			reclaim_rebate: 0,
-			_genesis_phantom_data: Default::default(),
 		}.build_storage().unwrap().0);
 		t.into()
 	}