Allow tcpdump to be run inside containers (e.g., mininet)

Change-Id: I278119c815388a38f3cb8e0bb44f4924554f07ec
diff --git a/seba-in-a-box/Makefile b/seba-in-a-box/Makefile
index 9576be5..bf3408b 100644
--- a/seba-in-a-box/Makefile
+++ b/seba-in-a-box/Makefile
@@ -245,6 +245,7 @@
 endif
 	sudo iptables -P FORWARD ACCEPT
 	sudo apparmor_parser -R /etc/apparmor.d/sbin.dhclient || true
+	sudo apparmor_parser -R /etc/apparmor.d/usr.sbin.tcpdump || true
 	touch $@
 	echo "SEBA-in-a-Box installation finished!"