Fix rpc_connection_call() locking to unbreak loopback transport.
Fix rpc_connection_call() locking to unbreak loopback transport.

twoporeguys/librpc,twoporeguys/librpc,twoporeguys/librpc,twoporeguys/librpc,twoporeguys/librpc,twoporeguys/librpc,twoporeguys/librpc,twoporeguys/librpc