Allow to use multimatching for alermanager routes

Change-Id: I2c0d439055efc0d218c8f247aea264d425fca838
diff --git a/prometheus/files/alertmanager.yml b/prometheus/files/alertmanager.yml
index c99956a..5c03fab 100644
--- a/prometheus/files/alertmanager.yml
+++ b/prometheus/files/alertmanager.yml
@@ -3,6 +3,9 @@
 {%- if route.receiver is defined -%}
 receiver: {{ route.receiver }}
 {%- endif -%}
+{%- if route.continue is defined %}
+continue: {{ route.continue }}
+{%- endif -%}
 {%- if route.group_by is defined %}
 group_by:
   {%- for group_by in route.group_by %}