Ephemeral keys worked fine while keys loaded from filesystem would
generate invalid signatures. This was caused by destroying private key
material during calls to Wallet.Close() and Account.Close(). Since these
calls do nothing except wiping the private key, we omit them now.
Responsibility for private key security is delegated to caller of getKey()
Signed-off-by: Vitaliy Potyarkin <v.potyarkin@yadro.com>
