BUG/MINOR: cache: fix memory leak in parse_cache_rule error path

When the filter config (fconf) allocation fails in parse_cache_rule,
the previously allocated cache_flt_conf (cconf) and its strdup'd name
string are not freed. The error path only freed cconf but not
cconf->c.name, causing a memory leak.

No backport is needed.

src/cache.c

@@ -1950,7 +1950,10 @@ static int parse_cache_rule(struct proxy *proxy, const char *name, struct act_ru
 	return 1;
 
   err:
-	free(cconf);
+	if (cconf) {
+		free(cconf->c.name);
+		free(cconf);
+	}
 	return 0;
 }