zabbix: update to 2.4.0, refresh patches

Signed-off-by: Christoph König <christoph.koenig@gmail.com>
Signed-off-by: Etienne CHAMPETIER <champetier.etienne@gmail.com>
admin/zabbix: put myself as maintainer

Signed-off-by: Etienne CHAMPETIER <champetier.etienne@gmail.com>
zabbix: update to 2.4.2

Remove 001-cross_compile.patch, it's fixed upstream (ZBX-5561)
Run tested on ar71xx

Signed-off-by: Etienne CHAMPETIER <champetier.etienne@gmail.com>
sqlite3: update to 3.8.7.1

Run tested on ar71xx

Signed-off-by: Etienne CHAMPETIER <champetier.etienne@gmail.com>