dnsmasq: add dhcphostsfile to ujail sandbox

The dhcphostsfile must be mounted into the (ujail) sandbox.
The file can not be accessed without this mount.

Signed-off-by: Ruben Jenster <rjenster@gmail.com>
(cherry picked from commit 936df715de3d33947ce38ca232b05c2bd3ef58f1)

package/network/services/dnsmasq/files/dnsmasq.init

@@ -1178,6 +1178,7 @@ dnsmasq_start()
 		[ ! -e "$logfacility" ] && touch "$logfacility"
 		procd_add_jail_mount_rw "$logfacility"
 	esac
+	[ -e "$hostsfile" ] && procd_add_jail_mount $hostsfile
 
 	procd_close_instance
 }