fundingmanager: make SendToPeer sync
fundingmanager: make SendToPeer sync

Since the funding flow requires messages to go through, make use of
sync version of SendToPeer. Using the async version we would risk that
the message was dropped and the process would stall (it would properly
continue after a restart though).

aakselrod/lnd,aakselrod/lnd,LightningNetwork/lnd,LightningNetwork/lnd