Fix auth multi-rule edgecase (#1418)

Co-authored-by: Ben Toogood <ben@micro.mu>

auth/service/service.go

@@ -219,7 +219,7 @@ func accessForRule(rule *rulePb.Rule, acc *auth.Account, res *auth.Resource) rul
 		}
 	}
 
-	return rulePb.Access_DENIED
+	return rulePb.Access_UNKNOWN
 }
 
 // listRules gets all the rules from the store which have an id