[Rspamd] Add custom IP whitelist template

data/conf/rspamd/custom/ip_wl.map

@@ -0,0 +1,4 @@
+# IP whitelist
+# 127.0.0.1
+# 1.2.3.4
+# ...

data/conf/rspamd/local.d/multimap.conf

@@ -96,3 +96,7 @@ MAILCOW_DOMAIN_HEADER_FROM {
   filter = "email:domain";  
   map = "redis://DOMAIN_MAP"; 
 }
+IP_WHITELIST {
+  type = "ip";
+  map = "$LOCAL_CONFDIR/custom/ip_wl.map";
+}