Fix s3.clean.uploads

[SmsS4]

What problem are we solving?

wrong jwt error in s3.clean.uploads
security.toml:

[jwt.signing]                      
key = "aaaaaaaaaaaa"           
expires_after_seconds = 30
                                   
[jwt.filer_signing]                
key = "bbbbbbbbbbb"           
expires_after_seconds = 30

> s3.clean.uploads -timeAgo 0
purge http://192.168.20.70:8888/buckets/test/.uploads/109f4b3c50d7b0df729d299bc6f8e9ef9066971f_19a49cbefa9c47cd8ecdf0f8993d1cdb?recursive=true&ignoreRecursiveError=true
failed cleanup uploads for bucket test: purge /buckets/test/.uploads/109f4b3c50d7b0df729d299bc6f8e9ef9066971f_19a49cbefa9c47cd8ecdf0f8993d1cdb: wrong jwt> 

How are we solving the problem?

weed shell is using jwt.signing.key for s3.clean.upload instead of jwt.filer_signing.key

How is the PR tested?

$ go run ./weed/weed.go master
$ go run ./weed/weed.go filer -s3 
$ go run ./weed/weed.go volume
$ dd if=/dev/zero of=test2 bs=1024MB count=1
$ aws --endpoint http://localhost:8333 s3 cp test2  s3://test
terminate aws cli with `SIGKILL`
$ echo "ls -a /buckets/test/.uploads/" | go run ./weed/weed.go shell
109f4b3c50d7b0df729d299bc6f8e9ef9066971f_8bb5348b440a47d9ae6cd9ed76c49995
echo "s3.clean.uploads -timeAgo 0" | go run ./weed/weed.go shell
purge http://192.168.20.70:8888/buckets/test/.uploads/109f4b3c50d7b0df729d299bc6f8e9ef9066971f_8bb5348b440a47d9ae6cd9ed76c49995?recursive=true&ignoreRecursiveError=true
$ echo "ls -a /buckets/test/.uploads/" | go run ./weed/weed.go shell

Checks

• I have added unit tests if possible.
• I will add related wiki document changes and link to this PR after merging.