reconnect: Fix repeated RECONNECT_CONNECT that was confusing JSON-RPC.

reconnect: Fix repeated RECONNECT_CONNECT that was confusing JSON-RPC.

reconnect_run() returns RECONNECT_CONNECT to tell the client that it should
start a new connection.  The client is then supposed to call
reconnect_connecting() to tell the FSM that it has begun a connection
attempt.  However, even after reconnect_connecting() was called,
reconnect_run() continued to return RECONNECT_CONNECT on each call until
the connection succeeded or failed.  This confused the jsonrpc_session
client, which expected that it would get a 0 return value from
reconnect_run() while the connection attempt was in progress.  Connections
that required multiple trips through the main poll loop, e.g. for SSL
negotiation, would often get cut off to start a second connection attempt.

This commit change reconnect_run() to return RECONNECT_CONNECT only until
the client tells it that a connection is in progress, which fixes the
problem.  This change entails a change to the internal details of the
reconnect FSM, so this commit also updates the reconnect tests to match.

Reported by Jeremy Stribling.