turris-webapps-netdata: restart lighttpd due to its changes

There is a file netdata.lighttpd and because of that, we need to restart
lighttpd to reflect those changes

(cherry picked from commit 05676d57)

web/turris-webapps-netdata/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=turris-webapps-netdata
 PKG_VERSION:=1.0
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_MAINTAINER:=CZ.NIC <packaging@turris.cz>
 PKG_LICENSE:=GPL-3.0-or-later
@@ -39,5 +39,10 @@ define Package/turris-webapps-netdata/install
 	$(CP) files/netdata.webapps $(1)/usr/share/turris-webapps/30_netdata.conf
 endef
 
+define Package/turris-webapps-netdata/postinst
+#!/bin/sh
+[ -n "$$IPKG_INSTROOT" ] || /etc/init.d/lighttpd restart
+endef
+
 $(eval $(call BuildPackage,turris-webapps-netdata))