Add /var/www to device table

The /var/www directory is listed in /etc/passwd in the skeleton target
filesystem as the home directory of the www-data user (uid 33).

In the final target filesystem, /var/www should be owned by www-data. This
is important for the lighttpd package, for example.

Signed-off-by: Simon Dawson <spdawson@gmail.com>
Acked-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

system/device_table.txt

@@ -10,6 +10,7 @@
 /tmp					d	1777	0	0	-	-	-	-	-
 /etc					d	755	0	0	-	-	-	-	-
 /home/default				d	2755	1000	1000	-	-	-	-	-
+/var/www				d	755	33	33	-	-	-	-	-
 /etc/shadow				f	600	0	0	-	-	-	-	-
 /etc/passwd				f	644	0	0	-	-	-	-	-
 /etc/network/if-up.d			d	755	0	0	-	-	-	-	-