[Rspamd] Move symbols to corresponding groups

data/conf/rspamd/local.d/metrics.conf

@@ -7,7 +7,7 @@ symbol "MAILCOW_AUTH" {
 	description = "mailcow authenticated";
 	score = -20.0;
 }
-group "bayes" {
+group "statistics" {
 	symbol "BAYES_SPAM" {
 		weight = 7.5;
 		description = "Message probably spam, probability: ";
@@ -38,6 +38,8 @@ symbol "SPOOFED_SENDER" {
 	description = "Sender is not authenticated but part of mailcow managed domains";
 	score = 1.0;
 }
+group "policies" {
   symbol "R_SPF_FAIL" {
     score = 4.0;
   }
+}