Set withdrawal key index to 0

Author: tsudmi

staking_deposit/credentials.py

@@ -54,7 +54,7 @@ def __init__(self, *, mnemonic: str, mnemonic_password: str,
         purpose = '12381'
         coin_type = '3600'
         account = str(index)
-        withdrawal_key_path = f'm/{purpose}/{coin_type}/{account}/0'
+        withdrawal_key_path = f'm/{purpose}/{coin_type}/0/0'
         self.signing_key_path = f'{withdrawal_key_path}/0'
 
         self.withdrawal_sk = mnemonic_and_path_to_key(