BUG/MINOR: checks: Support multiple HTTP expect rules

For an http-check ruleset, it should be allowed to set a chain of expect
rules. But an error is triggered during the post-parsing because of a wrong
test, inherited from the evaluation mode before the refactoring.

No need to backport.
diff --git a/src/checks.c b/src/checks.c
index b7d365b..8d371e6 100644
--- a/src/checks.c
+++ b/src/checks.c
@@ -4497,7 +4497,7 @@
 				  chk->index+1);
 			return 0;
 		}
-		else if (r->action != TCPCHK_ACT_SEND && chk->action == TCPCHK_ACT_EXPECT) {
+		else if (r->action != TCPCHK_ACT_SEND && r->action != TCPCHK_ACT_EXPECT && chk->action == TCPCHK_ACT_EXPECT) {
 			memprintf(errmsg, "unable to add http-check expect rule at step %d (missing send rule).",
 				  chk->index+1);
 			return 0;