BUG/MINOR: tcpcheck: Fix numbering of implicit HTTP send/expect rules

The index of the failing rule is reported in the health-check log message. The
rules index is also used in the check traces. But for implicit HTTP send/expect
rules, the index is wrong. It must be incremented by one compared to the
preceding rule.

This patch may be backported as far as 2.2.
diff --git a/src/tcpcheck.c b/src/tcpcheck.c
index 4e594a9..9610760 100644
--- a/src/tcpcheck.c
+++ b/src/tcpcheck.c
@@ -3637,7 +3637,7 @@
 			if (next && next->action == TCPCHK_ACT_CONNECT) {
 				LIST_DELETE(&chk->list);
 				LIST_INSERT(&next->list, &chk->list);
-				chk->index = next->index;
+				chk->index = next->index + 1;
 			}
 		}
 
@@ -3658,7 +3658,7 @@
 				goto out;
 			}
 			LIST_APPEND(px->tcpcheck_rules.list, &next->list);
-			next->index = chk->index;
+			next->index = chk->index + 1;
 		}
 	}