Pushkin notification service expect 'email' label

Change-Id: I44a4846c7b2e7c92446d70de2393937d4b365400
diff --git a/prometheus/server/alert/labels_add/route.yml b/prometheus/server/alert/labels_add/route.yml
index 47d9eea..651dab7 100644
--- a/prometheus/server/alert/labels_add/route.yml
+++ b/prometheus/server/alert/labels_add/route.yml
@@ -1,6 +1,6 @@
 parameters:
   _param:
-    prometheus_server_alert_label_route: mail
+    prometheus_server_alert_label_route: email
   prometheus:
     server:
       config: