capacity not updated

[yuchen-sun]

What happened:
When updates capacity for juicefs, the capacity of mount point does not updated.
What you expected to happen:
use df -h can get new capacity
How to reproduce it (as minimally and precisely as possible):

df -h
update juicefs capacity
df -h

Anything else we need to know?

Environment:

• JuiceFS version (use ./juicefs --version) or Hadoop Java SDK version:
  v0.17.0
• Cloud provider or hardware configuration running JuiceFS:
• OS (e.g: cat /etc/os-release):
  centos7.9
• Kernel (e.g. uname -a):
  3.10.0-1160.el7.x86_64
• Object storage (cloud provider and region):
  minio
• Redis info (version, cloud provider managed or self maintained):
• Network connectivity (JuiceFS to Redis, JuiceFS to object storage):
• Others:

[SandyXSD]

It takes at most one minute for mounted clients to recognize the change.
See: https://github.com/juicedata/juicefs/blob/main/pkg/meta/redis.go#L2077-L2079