packages: haveged: upgrade to 1.7c

This upgrades haveged from 1.4 to 1.7c (closes #13979)

Signed-off-by: Christian Pointner <equinox@chaos-at-home.org>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/packages@38485 3c298f89-4303-0410-b956-a3cf2f4a3e73