Fix bug: wrong parenthesis position in the condition
Fix bug returnPeer is not called if sequence_ == INITIATOR_SEND_KEY

In InitiatorMSEHandshakeCommand, when aborting connection, we must
return peer to the PeerStorage. But it is not done if sequence_ is
INITIATOR_SEND_KEY. This causes stale Peer objects whose usedBy()
returns true eventually occupies peer list and aria2 cannot make any
connections.