build: remove --disable-ipv6

Building with IPv6 disabled tends to break rather often and sprinkles
ugly #ifdefs around the code.  All that only to support systems where
the C library doesn't have IPv6 capability.

The year now being 2015, if this is a problem the thing to fix is the C
library.

The implication of this patch is that future patches need not care about
HAVE_IPV6 = 0 and may remove ifdefs gratuitously.  This patch doesn't
remove these ifdefs to not create unneccessary churn.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
Acked-by: Paul Jakma <paul@jakma.org>
diff --git a/buildtest.sh b/buildtest.sh
index 4859bf4..3bc25f2 100755
--- a/buildtest.sh
+++ b/buildtest.sh
@@ -4,22 +4,16 @@
 # builds some git commit of Quagga in some different configurations
 # usage: buildtest.sh [commit [configurations...]]
 
-basecfg="--prefix=/usr --enable-user=quagga --enable-group=quagga --enable-vty-group=quagga --enable-configfile-mask=0660 --enable-logfile-mask=0640 --enable-vtysh --sysconfdir=/etc/quagga --enable-exampledir=/etc/quagga/samples --localstatedir=/var/run/quagga --libdir=/usr/lib64/quagga --enable-ipv6 --enable-ripngd --enable-ospf6d --enable-rtadv --disable-static --enable-isisd --enable-multipath=0 --enable-babeld --enable-pimd"
+basecfg="--prefix=/usr --enable-user=quagga --enable-group=quagga --enable-vty-group=quagga --enable-configfile-mask=0660 --enable-logfile-mask=0640 --enable-vtysh --sysconfdir=/etc/quagga --enable-exampledir=/etc/quagga/samples --localstatedir=/var/run/quagga --libdir=/usr/lib64/quagga --enable-rtadv --disable-static --enable-isisd --enable-multipath=0 --enable-babeld --enable-pimd"
 
 configs_base="gcc|$basecfg"
 
-configs_nov6="gcc|$basecfg"
-configs_nov6="${configs_nov6/enable-ipv6/disable-ipv6}"
-configs_nov6="${configs_nov6/enable-ospf6d/disable-ospf6d}"
-configs_nov6="${configs_nov6/enable-ripngd/disable-ripngd}"
-configs_nov6="${configs_nov6/enable-babeld/disable-babeld}"
-
 configs_ext="gcc|$basecfg --enable-opaque-lsa --enable-ospf-te --enable-ospfclient --enable-isis-topology"
 configs_snmp="gcc|$basecfg --enable-opaque-lsa --enable-ospf-te --enable-ospfclient --enable-isis-topology --enable-snmp"
 configs_clang="clang|$basecfg --enable-opaque-lsa --enable-ospf-te --enable-ospfclient --enable-isis-topology"
 configs_icc="icc|$basecfg --enable-opaque-lsa --enable-ospf-te --enable-ospfclient --enable-isis-topology"
 
-defconfigs="base nov6 ext"
+defconfigs="base ext"
 net-snmp-config --version	&> /dev/null && defconfigs="$defconfigs snmp"
 clang --version			&> /dev/null && defconfigs="$defconfigs clang"
 icc --version			&> /dev/null && defconfigs="$defconfigs icc"