fix(mariadb): metric was renamed

fix(mariadb): rename metric in alert

mysql_info_schema_threads_seconds > mysql_info_schema_processlist_seconds
see prometheus/mysqld_exporter#603

Author: IvoGoman

common/mariadb/Chart.yaml

@@ -1,4 +1,4 @@
 apiVersion: v1
 description: A Helm chart for Kubernetes
 name: mariadb
-version: 0.7.13
+version: 0.7.14

common/mariadb/templates/alerts/_mysql.alerts.tpl

@@ -28,7 +28,7 @@
       summary: {{ include "fullName" . }} reports slow queries.
 
   - alert: {{ include "alerts.service" . | title }}MariaDBWaitingForLock
-    expr: (mysql_info_schema_threads_seconds{app=~"{{ include "fullName" . }}", state=~"waiting for lock"} / 1000  > 15)
+    expr: (mysql_info_schema_processlist_seconds{app=~"{{ include "fullName" . }}", state=~"waiting for lock"} / 1000  > 15)
     for: 10m
     labels:
       context: database