patch里启动mysql，volume使用的emptyDir，有问题

[yushanjin]

前面部署里启动mysql，使用的pvc，后面打patch，确使用了emptyDir。导致其他服务在mysql中初始化的database都没有，建议修改成一致
[root@xxxx patch]# cat mysql-persistent-storage.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: mysql
application-crd-id: kubeflow-pipelines
name: mysql
namespace: kubeflow
spec:
selector:
matchLabels:
app: mysql
application-crd-id: kubeflow-pipelines
strategy:
type: Recreate
template:
metadata:
labels:
app: mysql
application-crd-id: kubeflow-pipelines
spec:
containers:
- args:
- --ignore-db-dir=lost+found
- --datadir
- /var/lib/mysql
env:
- name: MYSQL_ALLOW_EMPTY_PASSWORD
value: "true"
image: registry.cn-shenzhen.aliyuncs.com/tensorbytes/ml-pipeline-mysql:5.7-f8fcd
name: mysql
ports:
- containerPort: 3306
name: mysql
resources:
requests:
cpu: 100m
memory: 800Mi
volumeMounts:
- mountPath: /var/lib/mysql
name: mysql-persistent-storage
serviceAccountName: mysql
nodeSelector:
app: kubeflow
volumes:
- name: mysql-persistent-storage
emptyDir:
{}

[shikanon]

@yushanjin thx，已修复 #96