[Rspamd] Use names instead of IPs

data/Dockerfiles/rspamd/settings.conf

@@ -1 +1 @@
-settings = "http://172.22.1.251:8081/settings.php";
+settings = "http://nginx:8081/settings.php";

data/conf/rspamd/local.d/greylist.conf

@@ -1 +1 @@
-whitelisted_ip = "http://172.22.1.251:8081/forwardinghosts.php";
+whitelisted_ip = "http://nginx:8081/forwardinghosts.php";