BUG/MEDIUM: config: ACL compatibility check on "redirect" was wrong

The check was made on "cond" instead of "rule->cond", so it never
emitted any warning since either the rule was NULL or it was set to
the last condition met.

This is 1.5-specific and the bug was introduced by commit 4baae248
in 1.5-dev17, so no backport is needed.
diff --git a/src/cfgparse.c b/src/cfgparse.c
index 2c2faf5..8c959de 100644
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -2689,7 +2689,7 @@
 
 		LIST_ADDQ(&curproxy->redirect_rules, &rule->list);
 		err_code |= warnif_rule_after_use_backend(curproxy, file, linenum, args[0]);
-		err_code |= warnif_cond_requires_resp(cond, file, linenum);
+		err_code |= warnif_cond_requires_resp(rule->cond, file, linenum);
 	}
 	else if (!strcmp(args[0], "use_backend")) {
 		struct switching_rule *rule;