BUG/MINOR: seemless reload: Fix crash when an interface is specified.

When doing a seemless reload, while receiving the sockets from the old process
the new process will die if the socket has been bound to a specific
interface.
This happens because the code that tries to parse the informations bogusly
try to set xfer_sock->namespace, while it should be setting wfer_sock->iface.

This should be backported to 1.8.
diff --git a/src/haproxy.c b/src/haproxy.c
index 0c823c4..d5235eb 100644
--- a/src/haproxy.c
+++ b/src/haproxy.c
@@ -1180,7 +1180,7 @@
 				goto out;
 			}
 			memcpy(xfer_sock->iface, &tmpbuf[curoff], len);
-			xfer_sock->namespace[len] = 0;
+			xfer_sock->iface[len] = 0;
 			curoff += len;
 		}
 		if (curoff + sizeof(int) > maxoff) {