remove haveged from SITE_PACKAGES

As per Gluon recommendation, remove haveged from SITE_PACKAGES:
> Starting with version 19.07 OpenWrt ships the urngd entropy daemon by
> default. It replaces the haveged daemon, for which we removed the
> support in Gluon. Remove haveged from your package selection.

Reference: https://gluon.readthedocs.io/en/latest/releases/v2020.2.html#site-mk

site.mk

@@ -20,7 +20,6 @@ GLUON_SITE_PACKAGES := \
 	gluon-neighbour-info \
 	gluon-mesh-vpn-fastd \
 	gluon-ssid-changer \
-	haveged \
 	iptables \
 	iwinfo \
 	ffs-set-segment \