MINOR: connection: check for send_proxy during the connect(), not the SI

It's cleaner to check for a pending send_proxy_ofs while establishing
the connection (which already checks it anyway) and not in the stream
interface.
diff --git a/include/proto/stream_interface.h b/include/proto/stream_interface.h
index 46d0c72..1cf9421 100644
--- a/include/proto/stream_interface.h
+++ b/include/proto/stream_interface.h
@@ -201,7 +201,7 @@
 	if (unlikely(!conn || !conn->ctrl || !conn->ctrl->connect))
 		return SN_ERR_INTERNAL;
 
-	ret = conn->ctrl->connect(conn, !channel_is_empty(si->ob), !!conn->send_proxy_ofs);
+	ret = conn->ctrl->connect(conn, !channel_is_empty(si->ob), 0);
 	if (ret != SN_ERR_NONE)
 		return ret;
 
@@ -209,10 +209,6 @@
 	if (si->flags & SI_FL_SRC_ADDR)
 		conn_get_from_addr(conn);
 
-	/* Prepare to send a few handshakes related to the on-wire protocol. */
-	if (conn->send_proxy_ofs)
-		conn->flags |= CO_FL_SI_SEND_PROXY;
-
 	/* we need to be notified about connection establishment */
 	conn->flags |= CO_FL_WAKE_DATA;
 
diff --git a/src/proto_tcp.c b/src/proto_tcp.c
index 1c55b6a..1f98445 100644
--- a/src/proto_tcp.c
+++ b/src/proto_tcp.c
@@ -257,6 +257,8 @@
  *   - 1 = delayed ACK if backend has tcp-smart-connect, regardless of data
  *   - 2 = delayed ACK regardless of backend options
  *
+ * Note that a pending send_proxy message accounts for data.
+ *
  * It can return one of :
  *  - SN_ERR_NONE if everything's OK
  *  - SN_ERR_SRVTO if there are no more servers
@@ -415,6 +417,9 @@
 		}
 	}
 
+	/* if a send_proxy is there, there are data */
+	data |= conn->send_proxy_ofs;
+
 #if defined(TCP_QUICKACK)
 	/* disabling tcp quick ack now allows the first request to leave the
 	 * machine with the first ACK. We only do this if there are pending
@@ -465,6 +470,10 @@
 	conn->flags  = CO_FL_WAIT_L4_CONN; /* connection in progress */
 	conn->flags |= CO_FL_ADDR_TO_SET;
 
+	/* Prepare to send a few handshakes related to the on-wire protocol. */
+	if (conn->send_proxy_ofs)
+		conn->flags |= CO_FL_SI_SEND_PROXY;
+
 	conn_ctrl_init(conn);       /* registers the FD */
 	conn_sock_want_send(conn);  /* for connect status */