change the comment and default value of the timezone's offset
change the comment and default value of the timezone's offset

This is so we avoid misleading the users

OHM-708 https://github.com/jembi/openhim-core-js/pull/997#discussion_r246392192 https://github.com/jembi/openhim-core-js/pull/997#discussion_r246391733

jembi/openhim-core-js,jembi/openhim-core-js