tcpdump: drop ipv6 flavour, cannot be disabled anymore

package/tcpdump/Makefile

@@ -16,7 +16,7 @@ PKG_SITES:=		http://www.tcpdump.org/release/
 
 DISTFILES:=		${PKG_NAME}-${PKG_VERSION}.tar.gz
 
-PKG_FLAVOURS_TCPDUMP:=	WITH_IPV6 WITH_CHROOT
+PKG_FLAVOURS_TCPDUMP:=	WITH_CHROOT
 PKGFD_WITH_IPV6:=	enable IPv6 support
 PKGFD_WITH_CHROOT:=	enable chrooting to /var/lib/tcpdump
 
@@ -27,11 +27,6 @@ $(eval $(call PKG_template,TCPDUMP,tcpdump,${PKG_VERSION}-${PKG_RELEASE},${PKG_D
 CONFIGURE_ENV+=		BUILD_CC="${TARGET_CC}" HOSTCC=${CC_FOR_BUILD} \
 			td_cv_buggygetaddrinfo="no"
 CONFIGURE_ARGS+=	--without-crypto
-ifneq (${ADK_PACKAGE_TCPDUMP_WITH_IPV6},)
-CONFIGURE_ARGS+=	--enable-ipv6
-else
-CONFIGURE_ARGS+=	--disable-ipv6
-endif
 ifneq (${ADK_PACKAGE_TCPDUMP_WITH_CHROOT},)
 CONFIGURE_ARGS+=	--with-chroot="/var/lib/tcpdump" --with-user="nobody"
 endif