DHCPv6: Replace the '-vv' option by '-v' for a test configuration

The '-vv' option is not currently used.

Author: fxlb

tests/TESTLIST

@@ -263,7 +263,7 @@ dhcpv6-ia-ta	dhcpv6-ia-ta.pcap	dhcpv6-ia-ta.out	-v
 dhcpv6-ntp-server	dhcpv6-ntp-server.pcap	dhcpv6-ntp-server.out	-v
 dhcpv6-sip-server-d	dhcpv6-sip-server-d.pcap	dhcpv6-sip-server-d.out -v
 dhcpv6-domain-list	dhcpv6-domain-list.pcap	dhcpv6-domain-list.out	-v
-dhcpv6-mud	dhcpv6-mud.pcap		dhcpv6-mud.out -vv
+dhcpv6-mud	dhcpv6-mud.pcap		dhcpv6-mud.out -v
 dhcpv6-rfc6355-duid-uuid dhcpv6-rfc6355-duid-uuid.pcap dhcpv6-rfc6355-duid-uuid.out -v
 dhcpv6-vendor-specific-information dhcpv6-vendor-specific-information.pcap dhcpv6-vendor-specific-information.out -v