Exclude snapshotted fields from being nilified

apps/explorer/lib/explorer/chain/import/runner/staking_pools.ex

@@ -134,8 +134,8 @@ defmodule Explorer.Chain.Import.Runner.StakingPools do
           staked_ratio: fragment("EXCLUDED.staked_ratio"),
           self_staked_amount: fragment("EXCLUDED.self_staked_amount"),
           staked_amount: fragment("EXCLUDED.staked_amount"),
-          snapshotted_self_staked_amount: fragment("EXCLUDED.self_staked_amount"),
-          snapshotted_staked_amount: fragment("EXCLUDED.staked_amount"),
+          snapshotted_self_staked_amount: pool.snapshotted_self_staked_amount,
+          snapshotted_staked_amount: pool.snapshotted_staked_amount,
           ban_reason: fragment("EXCLUDED.ban_reason"),
           was_banned_count: fragment("EXCLUDED.was_banned_count"),
           was_validator_count: fragment("EXCLUDED.was_validator_count"),

apps/explorer/lib/explorer/chain/import/runner/staking_pools_delegators.ex

@@ -106,7 +106,7 @@ defmodule Explorer.Chain.Import.Runner.StakingPoolsDelegators do
       update: [
         set: [
           stake_amount: fragment("EXCLUDED.stake_amount"),
-          snapshotted_stake_amount: fragment("EXCLUDED.snapshotted_stake_amount"),
+          snapshotted_stake_amount: delegator.snapshotted_stake_amount,
           ordered_withdraw: fragment("EXCLUDED.ordered_withdraw"),
           max_withdraw_allowed: fragment("EXCLUDED.max_withdraw_allowed"),
           max_ordered_withdraw_allowed: fragment("EXCLUDED.max_ordered_withdraw_allowed"),