[#69] frostfsid: Add new client init function

Signed-off-by: Denis Kirillov <d.kirillov@yadro.com>

frostfsid/client/client.go

@@ -22,7 +22,6 @@ import (
 type (
 	Client struct {
 		act      *actor.Actor
-		acc      *wallet.Account
 		contract util.Uint160
 	}
 
@@ -153,11 +152,18 @@ func New(ra actor.RPCActor, acc *wallet.Account, contract util.Uint160, opt Opti
 
 	return &Client{
 		act:      act,
-		acc:      acc,
 		contract: contract,
 	}, nil
 }
 
+// NewSimple creates a new Client using exising actor.Actor.
+func NewSimple(act *actor.Actor, contract util.Uint160) *Client {
+	return &Client{
+		act:      act,
+		contract: contract,
+	}
+}
+
 // StartTx inits transaction.
 func (c Client) StartTx() *commonclient.Transaction {
 	return commonclient.NewTransaction(c.contract)