hotfix: 500 on ada-holder/stake key voting power

Author: MSzalowski

govtool/backend/sql/get-stake-key-voting-power.sql

@@ -1,6 +1,6 @@
 SELECT
   COALESCE(SUM(tx_out.value), 0) AS voting_power,
-  stake_address.id as addr_id
+  encode(stake_address.hash_raw, 'hex') AS stake_key
 FROM
   stake_address
 JOIN