Change content-encoding type from 'zlib' to 'deflate'

[radsec]

To conform with the HTTP 1.1 RFC - https://tools.ietf.org/html/rfc2616#section-3.5. The following code must be changed as this will help this should be 'deflate' instead of 'zlib' even though the data is compressed with zlib.

Since 'deflate' is 'zlib', the same libraries for compression and decompression can be used.

Screenshot for reference and cli used to debug: sudo log stream --info --process santactl | tee -a santa-sync.log