environment variable is not passed to worker when sync.

[zhoucheng361]

What happened:
meta_url=$META_URL ./juicefs sync -v test/ jfs://meta_url/test/
--manager 172.20.0.1:8081 --worker sshuser@172.20.0.2,sshuser@172.20.0.3
--list-threads 10 --list-depth 5\

2023/07/20 17:02:57.798801 juicefs[299150] : launch worker command args: [ssh, sshuser@172.20.0.2, SSH_AUTH_SOCK=/tmp/ssh-asw9ph0BQJ/agent.291792, /tmp/juicefs, sync, -v, test/, jfs://meta_url/test/, --manager, 172.20.0.1:8081, --worker, sshuser@172.20.0.2,sshuser@172.20.0.3, --list-threads, 10, --list-depth, 5, --is-worker, --manager, 172.20.0.1:8081] [cluster.go:280]
2023/07/20 17:02:57.799061 juicefs[299150] : launch a worker on sshuser@172.20.0.2 [cluster.go:291]
2023/07/20 17:02:57.869411 juicefs[299150] : launch worker command args: [ssh, sshuser@172.20.0.3, SSH_AUTH_SOCK=/tmp/ssh-asw9ph0BQJ/agent.291792, /tmp/juicefs, sync, -v, test/, jfs://meta_url/test/, --manager, 172.20.0.1:8081, --worker, sshuser@172.20.0.2,sshuser@172.20.0.3, --list-threads, 10, --list-depth, 5, --is-worker, --manager, 172.20.0.1:8081] [cluster.go:280]
2023/07/20 17:02:57.869650 juicefs[299150] : launch a worker on sshuser@172.20.0.3 [cluster.go:291]
sshuser@172.20.0.2 2023/07/20 09:02:58.004948 juicefs[44] : maxprocs: Leaving GOMAXPROCS=8: CPU quota undefined [maxprocs.go:47]
sshuser@172.20.0.2 2023/07/20 09:02:58.005410 juicefs[44] : Creating file storage at endpoint /home/sshuser/test/ [object_storage.go:171]
sshuser@172.20.0.2 2023/07/20 09:02:58.005465 juicefs[44] : Ensure directory /home/sshuser/test/ [file.go:339]
sshuser@172.20.0.2 2023/07/20 09:02:58.005689 juicefs[44] : Creating jfs storage at endpoint meta_url [object_storage.go:171]
sshuser@172.20.0.2 2023/07/20 09:02:58.005708 juicefs[44] : Meta address: redis://meta_url [interface.go:497]
sshuser@172.20.0.3 2023/07/20 09:02:58.072891 juicefs[45] : maxprocs: Leaving GOMAXPROCS=8: CPU quota undefined [maxprocs.go:47]
sshuser@172.20.0.3 2023/07/20 09:02:58.073322 juicefs[45] : Creating file storage at endpoint /home/sshuser/test/ [object_storage.go:171]
sshuser@172.20.0.3 2023/07/20 09:02:58.073361 juicefs[45] : Ensure directory /home/sshuser/test/ [file.go:339]
sshuser@172.20.0.3 2023/07/20 09:02:58.073537 juicefs[45] : Creating jfs storage at endpoint meta_url [object_storage.go:171]
sshuser@172.20.0.3 2023/07/20 09:02:58.073558 juicefs[45] : Meta address: redis://meta_url [interface.go:497]
sshuser@172.20.0.2 2023/07/20 09:03:39.187362 juicefs[44] : parse info: dial tcp: lookup meta_url on 127.0.0.11:53: server misbehaving [redis.go:3547]
sshuser@172.20.0.3 2023/07/20 09:03:39.254457 juicefs[45] : parse info: dial tcp: lookup meta_url on 127.0.0.11:53: server misbehaving [redis.go:3547]

What you expected to happen:

How to reproduce it (as minimally and precisely as possible):

Anything else we need to know?

Environment:

• JuiceFS version (use juicefs --version) or Hadoop Java SDK version:
• Cloud provider or hardware configuration running JuiceFS:
• OS (e.g cat /etc/os-release):
• Kernel (e.g. uname -a):
• Object storage (cloud provider and region, or self maintained):
• Metadata engine info (version, cloud provider managed or self maintained):
• Network connectivity (JuiceFS to metadata engine, JuiceFS to object storage):
• Others: