accounts: update the service's UpdateAccount method

... to take a more strict btcutil.Amount type for the account balance
parameter.

Author: ellemouton

accounts/rpcserver.go

@@ -122,7 +122,8 @@ func (s *RPCServer) UpdateAccount(ctx context.Context,
 
 	// Ask the service to update the account.
 	account, err := s.service.UpdateAccount(
-		ctx, accountID, req.AccountBalance, req.ExpirationDate,
+		ctx, accountID, btcutil.Amount(req.AccountBalance),
+		req.ExpirationDate,
 	)
 	if err != nil {
 		return nil, err

accounts/service.go

@@ -7,6 +7,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/btcsuite/btcd/btcutil"
 	"github.com/btcsuite/btcd/chaincfg"
 	"github.com/lightninglabs/lndclient"
 	"github.com/lightningnetwork/lnd/channeldb"
@@ -299,7 +300,7 @@ func (s *InterceptorService) NewAccount(ctx context.Context,
 // UpdateAccount writes an account to the database, overwriting the existing one
 // if it exists.
 func (s *InterceptorService) UpdateAccount(ctx context.Context,
-	accountID AccountID, accountBalance,
+	accountID AccountID, accountBalance btcutil.Amount,
 	expirationDate int64) (*OffChainBalanceAccount, error) {
 
 	s.Lock()