fixes GELF format according to specs
fixes GELF format according to specs

GELF formatted messages need to be \0 ended. At least for sending over
TCP.

Open-Party/python-beaver,imacube/python-beaver,timstoop/python-beaver,jlambert121/beaver,davidmoravek/python-beaver,doghrim/python-beaver,timstoop/python-beaver,PierreF/beaver,PierreF/beaver,josegonzalez/python-beaver,doghrim/python-beaver,python-beaver/python-beaver,jlambert121/beaver,imacube/python-beaver,rajmarndi/python-beaver,rajmarndi/python-beaver,Open-Party/python-beaver,python-beaver/python-beaver,josegonzalez/python-beaver,davidmoravek/python-beaver