BUG/MEDIUM: checks: Refresh the conn-stream and the connection after a connect

When a connect rule is evaluated, the conn-stream and the connection must be
refreshed in tcpcheck_main(). Otherwise, in case of synchronous connect, these
variables point on outdated values (NULL for the first connect or released
otherwise).

No backport needed.
diff --git a/src/checks.c b/src/checks.c
index c3d117e..d377b17 100644
--- a/src/checks.c
+++ b/src/checks.c
@@ -2721,6 +2721,10 @@
 				retcode = -1; /* do not reuse the fd in the caller! */
 			}
 			eval_ret = tcpcheck_eval_connect(check, rule);
+
+			/* Refresh conn-stream and connection */
+			cs = check->cs;
+			conn = cs_conn(cs);
 			must_read = 1; last_read = 0;
 			break;
 		case TCPCHK_ACT_SEND: