Changes

stream_cli: Announce failed connect() if reconnect is disabled

One of the use cases of disabling reconnect in osmo_stream_cli is
because the user of the stream wants to control the reconnect based on
upper layer contexts. In this case, though, if there's a failure during
connect() time, the user won't get any notification and hence stay
disconnected forever. Instead, inform the user through the
disconnect_cb().

Change-Id: I69a5f7c3c7cea97d31e2fa03e8c32ce806285eb6