[stable/mysql] service endpoints shouldn't depend on /metrics (#6725)

* MySQL service endpoints shouldn't depend on /metrics

Problem: mysqld_metrics doesn't respond on "/metrics" when dropping big database. As result service has no endpoint because metrics cann't be queried.
Solution: use "/" for httpGet probes on metrics which will return only landing page with http code 200.

* Update Chart.yaml

stable/mysql/Chart.yaml

@@ -1,5 +1,5 @@
 name: mysql
-version: 0.10.0
+version: 0.10.1
 appVersion: 5.7.14
 description: Fast, reliable, scalable, and easy to use open-source relational database
   system.

stable/mysql/templates/deployment.yaml

@@ -145,13 +145,13 @@ spec:
           containerPort: 9104
         livenessProbe:
           httpGet:
-            path: /metrics
+            path: /
             port: metrics
           initialDelaySeconds: {{ .Values.metrics.livenessProbe.initialDelaySeconds }}
           timeoutSeconds: {{ .Values.metrics.livenessProbe.timeoutSeconds }}
         readinessProbe:
           httpGet:
-            path: /metrics
+            path: /
             port: metrics
           initialDelaySeconds: {{ .Values.metrics.readinessProbe.initialDelaySeconds }}
           timeoutSeconds: {{ .Values.metrics.readinessProbe.timeoutSeconds }}