COMPRESS received NO response: Compression already active: DEFLATE

[Per olof Ljungmark]

sync_client starts with compression enable (-z) but as soon as it
restarts, it fails to enable it.

Server side at first start

syncserver[87122]: accepted connection
syncserver[87122]: cmdloop(): startup
syncserver[87122]: login: [client-IP] cyrus PLAIN User logged in
syncserver[87122]: created decompress buffer of 4102 bytes
syncserver[87122]: created compress buffer of 4102 bytes

Client at first restart

sync_client[49902]: sync_client RESTART succeeded
sync_client[49902]: COMPRESS received NO response: Compression already
active: DEFLATE
sync_client[49902]: Failed to enable compression, continuing uncompressed

cyrus-imap is 2.4.17