remove uncompressed data magic header

default to returning uncompressed data without checking for magic header for
compliant with graylog2 server. Relevant piece for graylog2 server is at
https://github.com/Graylog2/graylog2-server/blob/edd1a66a2f9924e39b217df4c94327a86b8fecab/graylog2-server/src/main/java/org/graylog2/inputs/codecs/gelf/GELFMessage.java#L147

Signed-off-by: Daniel Dao <dqminh@cloudflare.com>

Version 0.2.0

Version 0.1.0

Version 0.0.1