Change query for the MongoDBNoPrimaryMember alert

Change-Id: I78d5e038c1d147ec200b3f824fef440db5ec4207
diff --git a/mongodb/meta/prometheus.yml b/mongodb/meta/prometheus.yml
index 6da2924..9a174f2 100644
--- a/mongodb/meta/prometheus.yml
+++ b/mongodb/meta/prometheus.yml
@@ -25,7 +25,7 @@
         description: "All MongoDB services are down for 1 minute."
     MongoDBNoPrimaryMember:
       if: >-
-        absent({__name__=~"mongodb.*",state="PRIMARY"})
+        absent(mongodb_state == 1)
       for: 1m
       labels:
         severity: critical
@@ -34,4 +34,4 @@
         summary: "MongoDB cluster has no primary member"
         description: "MongoDB cluster has no primary member for 1 minute."
 {%- endraw %}
-{%- endif %}
\ No newline at end of file
+{%- endif %}